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10) 9001 
 
 Bureau of Mines Information Circular/1985 
 
 Laboratory Wear Testing Capabilities 
 of the Bureau of Mines 
 
 By R. Blickensderfer, J. H. Tylczak, and B. W. Madsen 
 
 UNITED STATES DEPARTMENT OF THE INTERIOR 
 
 .751 
 
 AflNES 75TH A^^ 
 
J nVorrnati on circu-ic^r {^Unittd ouxres, (e>arca.fcc OT I I'ne^y 
 
 information Circular 9001 
 
 Laboratory Wear Testing Capabilities 
 of the Bureau of Mines 
 
 By R. Blickensderfer, J. H. Tylczak, and B. W. Madsen 
 
 UNITED STATES DEPARTMENT OF THE INTERIOR 
 William P. Clark, Secretary 
 
 BUREAU OF MINES 
 Robert C. Horton, Director 
 

 UNIT OF MEASURE 
 
 ABBREVIATIONS USED 
 
 IN THIS REPORT 
 
 °c 
 
 degree Celsius 
 
 L/min 
 
 liter per minute 
 
 cm 
 
 centimeter 
 
 m 
 
 "'" ^t\l^^ 
 
 cm^ 
 
 square centimeter 
 
 mg 
 
 milligram 1 ' 
 
 c/min 
 
 cycle per minute 
 
 mln 
 
 minute / ^' ^,1 
 millimeter -h, ' 
 
 deg 
 
 degree 
 
 mm 
 
 g 
 
 gram 
 
 mm' 
 
 cubic millimeter 
 
 g/mln 
 
 gram per minute 
 
 m/mln 
 
 meter per minute 
 
 HB 
 
 Brinell hardness 
 
 mm'/m 
 
 cubic millimeter per meter 
 
 h 
 
 hour 
 
 vm 
 
 micrometer 
 
 HRC 
 
 Rockwell C hardness 
 
 m/s 
 
 meter per second 
 
 in 
 
 inch 
 
 N 
 
 newt on 
 
 J 
 
 joule 
 
 pet 
 
 percent 
 
 kg 
 
 kilogram 
 
 psl 
 
 pound per square inch 
 
 kPa 
 
 kilopascal 
 
 rpm 
 
 revolution per minute 
 
 kW 
 
 kilowatt 
 
 s 
 
 second 
 
 L 
 
 liter 
 
 wt pet 
 
 weight percent 
 
 Library of Congress Cataloging in Publication Data: 
 
 Blickensderfer, Robert 
 
 Laboratory wear testing capabilities of the Bureau of Mines. 
 
 (Information circular ; 9001) 
 
 Bibliography: p. 34-36. 
 
 Supt. of Docs, no.: I 28.27:9001. 
 
 1. Mechanical wear— Testing. I. Tylczak, J. H. (Joseph H.). II. 
 Madsen, B. W. (Brent W.). III. Title. IV. Series: Information circu- 
 lar (United States. Bureau of Mines) ; 9001. 
 
 TN295.U4 [TA418.4] 622s [622'.028] 84-600209 
 
CONTENTS 
 
 Page 
 
 Abstract 1 
 
 Introduction 2 
 
 Description of tests and equipment 2 
 
 Abrasive wear 3 
 
 Dry-sand, rubber-wheel abrasive wear test 3 
 
 DSRW equipment and specimen. 4 
 
 DSRW procedure 4 
 
 DSRW results and discussion 5 
 
 Taber Abraser test 5 
 
 Taber Abraser equipment and specimens 5 
 
 Taber Abraser procedure 6 
 
 Abrasion resistance test of refractory materials 7 
 
 Dry-particle erosive wear test 7 
 
 Dry-particle equipment and specimen 7 
 
 Dry-particle procedure. 9 
 
 Dry-particle typical results 9 
 
 Elevated-temperature, dry-particle erosive wear test 10 
 
 Elevated-temperature erosive equipment and specimens 11 
 
 Elevated-temperature erosive procedure 11 
 
 Elevated-temperature erosive results 11 
 
 Low-angle slurry pot test 12 
 
 Slurry pot equipment and specimens 13 
 
 Slurry pot procedure 16 
 
 Slurry pot results 16 
 
 Jaw crusher gouging abrasion test 17 
 
 Jaw crusher equipment and specimen 17 
 
 Jaw crusher procedure 18 
 
 Jaw crusher typical results 18 
 
 Ball mill wear test 20 
 
 Ball mill equipment and specimens 20 
 
 Ball mill procedure 21 
 
 Ball mill results and discussion 21 
 
 Pin-on-drum abrasive wear test 22 
 
 Pln-on-drum equipment and specimen 22 
 
 Fln-on-drum procedure 23 
 
 Pin-on-drum results and discussion 24 
 
 High-speed impact-gouging test 25 
 
 High-speed Impact equipment and specimen 25 
 
 High-speed impact procedure 26 
 
 Impact-spalling wear 26 
 
 Ball-on-block Impact-spalling test 27 
 
 Ball-on-block equipment and specimen 27 
 
 Ball-on-block procedure 30 
 
 Ball-on-block results and discussion 30 
 
 Ball-on-ball impact-spalling test 31 
 
 Ball-on-ball equipment and specimens 31 
 
 Ball-on-ball procedure 32 
 
 Ball-on-ball results and discussion 32 
 
 Summary 32 
 
 References 34 
 
ii 
 
 ILLUSTBIATIONS 
 
 Page 
 
 1 . Dry-sand, rubber-wheel abrasive wear test machine 4 
 
 2. Taber Abraser test, schematic 6 
 
 3 . Wear pattern produced by the Taber Abraser 6 
 
 4. Abrasion resistance test of refractory materials, schematic 8 
 
 5. Dry-particle erosive wear test apparatus , schematic 9 
 
 6. Dry-particle erosive wear test, specimen chamber 10 
 
 7. Elevated— temperature erosion tester, schematic 12 
 
 8. Low-angle slurry pot equipment, schematic 14 
 
 9 . Low-angle slurry pot test equipment 15 
 
 10. Jaw crusher gouging wear test machine, schematic 18 
 
 11. Jaw crusher gouging wear test machine..... 19 
 
 12. Small ball mill with specimens, liquid, and rock 21 
 
 13. Ball mill test equipment, schematic 21 
 
 14. Pin-on-drum abrasive wear test machine, schematic 23 
 
 15. Pin-on-drum abrasive wear test machine 24 
 
 1 6. High-speed impact-gouging test machine , schematic 26 
 
 17. High-speed impact-gouging test machine 27 
 
 18 . Ball-on-block impact-spalling test machine , schematic 28 
 
 19. Ball-on-block impact-spalling test machine 29 
 
 20. Ball-on-ball impact-spalling test machine, schematic... 31 
 
 TABLES 
 
 1. Standard conditions for the dry-sand, rubber-wheel abrasion test 4 
 
 2 . Typical dry-sand , rubber-wheel abrasive wear data. 5 
 
 3. Typical dry-particle erosive wear data 9 
 
 4 . Hot erosive wear of several materials 11 
 
 5. Typical low-angle slurry wear data for several metallic specimens 16 
 
 6. Typical Jaw crusher gouging wear data 20 
 
 7. Ball mill erosion-corrosion of several materials 22 
 
 8 . Typical pin-on-drum wear test data 24 
 
 9 . Typical ball-on-block impact-spalling data 30 
 
 10. Summary of Bureau of Mines wear tests 33 
 
 1 1 . Summary of wear tes t parameters 33 
 
LABORATORY WEAR TESTING CAPABILITIES OF THE BUREAU OF MINES 
 
 By R. Blickensderfer, ^ J. H. Tylczak, ^ and B. W. Madsen ^ 
 
 ABSTRACT 
 
 The laboratory wear testing capabilities of the Bureau of Mines are 
 described. Wear tests are used to support the Bureau's research ef- 
 forts toward reducing the wear of equipment used for mining and miner- 
 als processing and any wear involving a loss of strategic or critical 
 materials. The emphasis is on abrasive wear because it accounts for 
 most of the wear losses that occur in mining and minerals processing 
 equipment. Spalling wear, caused by repetitive impact in grinding 
 equipment, also is included. Ten abrasive wear tests, including high- 
 stress and low-stress and two-body and three-body conditions, are 
 described: dry-sand, rubber-wheel abrasive wear; Taber Abraser; abra- 
 sion resistance of refractory materials; dry-particle erosive wear; 
 elevated-temperature, dry-particle erosive wear; low-angle slurry 
 pot; jaw crusher gouging wear; ball mill wear; pin-on-drum abrasive 
 wear; and high-speed impact gouging. Two repetitive impact tests are 
 described: ball-on-block impact-spalling and ball-on-ball impact- 
 spalling. Test equipment, procedures, and specimens are described, and 
 typical test results are presented and discussed. 
 
 ^Metallurgist, Albany Research Center, Bureau of Mines, Albany, OR. 
 
INTRODUCTION 
 
 Wear is a major problem in the mining 
 industry and occurs on a wide variety 
 of items, such as excavator teeth, rock 
 drill bits, crushers, slushers, ball 
 mills and rod mills , chutes , slurry 
 pumps, and cyclones. Wear results in a 
 significant cost to the mining industry 
 in terms of direct replacement costs, 
 downtime, and maintenance. The Bureau of 
 Mines is conducting research on various 
 types of wear processes and materials. 
 Wear mechanisms and the effects of vari- 
 ables such as alloy composition and heat 
 treatment are being studied with the ul- 
 timate aim of devising alloy systems that 
 reduce wear and significantly reduce the 
 loss of critical and strategic metals. 
 In order to support this research, a var- 
 iety of laboratory test equipment has 
 been purchased or constructed. 
 
 Although numerous types of wear tests 
 have been reported, most are beset by 
 lack of reproducibility or are too spe- 
 cialized to be of general interest. Only 
 eight wear test practices have been pub- 
 lished by the American Society for Test- 
 ing and Materials (ASTM) , although others 
 are in process. The G.2 committee of 
 ASTM, which is concerned with all types 
 of wear, is devoting considerable effort 
 toward developing wear test standard 
 practices and procedures. The Bureau is 
 working with the G.2 committee in this 
 effort. The ASTM has published an evalu- 
 ation of wear testing (Jl^)^ and, more re- 
 cently, a volume describing a wide range 
 of types of wear tests (_2 ) . Borik O) 
 compared several abrasion tests on a var- 
 iety of abrasion-resistant materials. 
 
 An ideal laboratory wear test would 
 be small in scale, produce highly repro- 
 ducible data quickly, and simulate a 
 
 wide range of field conditions. The test 
 results should predict the wear of a 
 material in actual service. Such a test 
 is difficult to achieve because wear 
 processes are dependent on a number of 
 variables that are affected by time 
 and scale. Some of these factors are 
 frictional heating (lowering the flow 
 stress), work hardening rate, size and 
 nature of wear debris, nature of abrasive 
 particles, microstructure of the materi- 
 al, and environmental interactions. 
 
 Consequently, hundreds of wear tests 
 have been devised, each an attempt by an 
 investigator to closely simulate a given 
 wear situation while producing signifi- 
 cant wear in a short time. There is a 
 need to standardize and minimize the 
 types of wear tests in order to make in- 
 terlaboratory comparisons and to reduce 
 the number of tests and types of test 
 specimens required. At the same time, 
 there is a need for the tests to more 
 closely simulate a broader range of field 
 conditions. 
 
 It is hoped that the following descrip- 
 tion of wear tests used by the Bureau 
 will be helpful to other organizations 
 involved in wear testing and wear re- 
 search. The comparison of test parame- 
 ters such as specimen size, duration of 
 test, surface speed, etc. may be partic- 
 ularly useful to those attempting to se- 
 lect a suitable wear test. Also, this 
 report may stimulate further ideas in 
 wear testing and wear research that will 
 eventually help reduce the tremendous 
 losses in materials that result from 
 equipment wear in mining and minerals 
 processing in the United States as well 
 as other countries. 
 
 DESCRIPTION OF TESTS AND EQUIPMENT 
 
 The Bureau of Mines has a total of 12 
 types of wear test units in use. Ten of 
 
 — ^ — 
 
 ''Underlined numbers in parentheses re- 
 fer to items in the list of references at 
 the end of this report. 
 
 these units are located at the Albany 
 (OR) Research Center, where considerable 
 research is being conducted on wear. The 
 other two units are at the Rolla (MO) and 
 Tuscaloosa (AL) Research Centers. Most 
 of the Bureau's tests are related to 
 
abrasive wear, including erosive wear and 
 slurry wear, because most wear problems 
 in mining and minerals processing are 
 caused by abrasive materials. Two tests 
 involve impact-spalling wear — a major 
 wear problem in crushing and grinding 
 equipment. Other types of wear, such as 
 adhesive wear and lubricated wear, are 
 not being addressed. One study of wear 
 between quartz and steel was conducted 
 in 1976 at the Twin Cities (MN) Research 
 Center (4^) , but the pin-wear test equip- 
 ment that was used no longer exists. 
 Similar pin-wear test equipment belonging 
 to the University of Maryland was recent- 
 ly used at the Avondale (MD) Research 
 Center for evaluating molybdenum diboride 
 coatings. 
 
 Among the wear tests described, the 
 dry-sand, rubber-wheel abrasion test is 
 an ASTM standard practice (_5) and the 
 abrasion resistance of refractory materi- 
 als is an ASTM standard test method (6). 
 Two of the tests, the jaw crusher gouging 
 abrasion test and the dry-particle ero- 
 sion standard practice, were recently 
 published by the ASTM. Of the remaining 
 eight tests, three are novel tests de- 
 vised by the Bureau, namely, the ball-on- 
 ball impact-spalling test, the high-speed 
 impact-gouging wear test, and the low- 
 angle slurry pot test. The other five 
 types of tests described are not ASTM 
 standards but have been reported by other 
 laboratories. In several cases, the Bu- 
 reau has modified or improved the earlier 
 tests. 
 
 are not pertinent to the thrust of the 
 Bureau's research on wear of mining 
 equipment . 
 
 ABRASIVE WEAR 
 
 Abrasive wear tests are frequently 
 classified by the type of test equipment 
 used; however, they can be classified in 
 more general terms by the stress level 
 and the geometrical arrangement of the 
 components of the system (7^, pp. 8-9). 
 If the load is sufficient to fracture the 
 abrasive particles, the wear is called 
 high-stress abrasive wear; if the parti- 
 cles do not fracture significantly, it 
 is called low-stress abrasive wear. The 
 distinction between low-stress and high- 
 stress conditions is not sharp. As for 
 geometrical arrangement, if the abrasive 
 particle is in contact with only one 
 other object, it is called two-body abra- 
 sive wear. If the particle is engaged 
 by more than one other object, such as 
 another wear surface or other abrasive 
 particles, it is called three-body wear. 
 Although the abrasive material is normal- 
 ly harder than the wear object, this is 
 not a necessary condition for classify- 
 ing the wear as abrasive wear. Erosive 
 wear is often categorized separately from 
 abrasive wear. However, the erosive wear 
 described in this report involves only 
 solid particle erosion and therefore is 
 considered as a type of abrasive wear. 
 
 Dry-Sand, Rubber-Wheel 
 Abrasive Wear Test 
 
 Not included in this report are the 
 frictional ignition tests at the Twin 
 Cities, Albany, Avondale, and Pittsburgh 
 (PA) Research Centers and the Los Angeles 
 abrasion machine at Tuscaloosa Research 
 Center. Although wear is inherent in the 
 frictional ignition of methane-air mix- 
 tures, the frictional ignition equipment 
 is not used at present to study wear pro- 
 cesses or wear mechanisms although it may 
 be so used in the future. The Los Ange- 
 les machine is for evaluating the abra- 
 sion resistance of aggregates, such as 
 those used for concrete or asphalt pav- 
 ing. The tests, ASTM C131-81 and C565, 
 
 The dry-sand, rubber-wheel (DSRW) abra- 
 sion test apparatus simulates low-stress, 
 three-body abrasive wear. This type of 
 wear occurs in the mining industry in 
 linkages, pivot pins, and wire ropes, 
 which suffer slow wear from the sliding 
 and rolling action of abrasive fragments 
 of rock and ore trapped between metal 
 surfaces. Because this type of wear is 
 slow, field trials alone would be too 
 slow for evaluating new materials. The 
 DSRW abrasion test is quick and gives a 
 reasonable correlation with field tests. 
 Even before the test became an ASTM stan- 
 dard (G65-81) in 1980 (5), it had been 
 
used by a number of laboratories for many 
 years. Since becoming an ASTM standard, 
 it has become probably the most popular 
 abrasive wear test in the United States. 
 
 The Society of Automotive Engineers 
 (SAE) has developed but has not published 
 a wet-sand abrasion test (8^) that is sim- 
 ilar to the ASTM dry-sand test. Some ma- 
 chines have been built to run both tests. 
 SAE's wet-sand test has the advantage 
 that the specimen does not heat as much 
 as do the samples in a dry-sand test. 
 
 DSRW Equipment and Specimen 
 
 The basic ASTM machine consists of a 
 rubber-rimmed steel wheel, 228.6 mm in 
 diam by 12.7 mm wide, that turns at 200 
 rpm during a test; a sand hopper con- 
 nected by a tube to a nozzle that allows 
 a 250- to 350-g/min sand flow; a revolu- 
 tion counter that stops the drive motor 
 after a set number of revolutions; and a 
 weighted lever arm that holds the spec- 
 imen and produces a horizontal force 
 against the wheel where the sand is flow- 
 ing. The sand is a 50- to 70-mesh silica 
 test sand. The hardness of the rubber on 
 the wheel must be durometer A-60±2. 
 
 The Bureau's machine includes a strain 
 gauge and a tachometer, as shown in fig- 
 ure 1 , although they are not part of 
 the ASTM standard. The strain gauge sup- 
 ports the lever arm assembly at its pivot 
 point, which is on a vertical line 
 through the specimen-wheel interface. 
 This allows measurement of the frictional 
 force on the specimen during the wear 
 test. The tachometer and a variable- 
 speed drive make it possible to maintain 
 a constant surface velocity on the rubber 
 wheel as the diameter of the wheel de- 
 creases through either wear or surface 
 dressing. 
 
 A typical test specimen is a rectan- 
 gle, 25 by 76 mm, that is 3 to 13 mm 
 thick. The wear surface is ground flat 
 with a surface finish of at least 0.8 
 urn. The density of the test material 
 must be known, to calculate the vol- 
 ume lost. The relatively simple shape 
 
 -Sand hopper 
 
 Sand nozzle 
 Tachometer 
 
 -Strain gauge 
 ■Pivot point 
 
 Weight 
 
 Specimen 
 Rubber-lined wheel 
 
 FIGURE 1. - Dry-sand, rubber-wheel abrasive 
 wear test machine. 
 
 of the test specimen is conducive to 
 specimen preparation. Specimens of pure 
 metals, steels, white cast irons, weld 
 overlays, plastics, and ceramics have 
 been made and tested. 
 
 DSRW Procedure 
 
 The equipment has two test parameters: 
 the sliding distance (number of wheel 
 revolutions) and the specimen load. The 
 ASTM recognizes four procedures using 
 these parameters, as shown in table 1. 
 
 TABLE 1. - Standard conditions for the 
 dry-sand, rubber-wheel abrasion test 
 
 ASTM 
 procedure 
 
 Force on 
 specimen, 
 
 N 
 
 Wheel 
 revolu- 
 tions ' 
 
 Distance 
 
 abraded, 
 
 m 
 
 A 
 
 130 
 
 130 
 
 130 
 
 45 
 
 6,000 
 
 2,000 
 
 100 
 
 6,000 
 
 4,309 
 
 B 
 
 1,436 
 
 c 
 
 71.8 
 
 D 
 
 4,309 
 
 ^ Based on a diameter of 228.6 
 Must be increased with wheel wear. 
 
A test consists of eight steps: 
 
 (1) clean and weigh the specimen, 
 
 (2) mount the specimen in the lever arm 
 fixture and load the arm, (3) start the 
 sand flow through the nozzle, (4) start 
 the rubber-wheel drive motor, (5) release 
 the lever arm so the specimen contacts 
 the wheel and start the revolution coun- 
 ter, (6) stop the motor (automatic) and 
 sand flow, (7) remove the specimen, and 
 (8) clean and reweigh the specimen. From 
 the weight loss and density of the 
 material, the volume loss is calculated. 
 The test is repeated one or more times. 
 The coefficient of variation on a mate- 
 rial must not exceed 7 pet to meet 
 ASTM specifications. 
 
 DSRW Results and Discussion 
 
 Most of the Bureau's testing has been 
 with a 130-N load on the specimen and 
 2,000 revolutions of the rubber wheel 
 (ASTM procedure B) . Typical volume 
 losses have ranged from 5 mm^ for sin- 
 tered AI2O3 to 188 mm^ for pure iron, 
 with losses for most steels ranging from 
 30 to 120 mm^. The reproducibility of 
 the test is best for volume losses in the 
 range of 20 to 100 mm^. 
 
 In tests in which less than 20 mm-' is 
 lost, any small material inhomogeneities 
 are exaggerated; therefore, a more severe 
 test should be run by using either a 
 greater sliding distance or more load. 
 Above a 100-mm^ loss, the groove becomes 
 so deep that it may contact the edge of 
 the rubber wheel and cause erratic re- 
 sults. Therefore, a less severe proce- 
 dure may be desired. Using another pro- 
 cedure has a disadvantage in that test 
 
 results cannot be directly compared among 
 different procedures. 
 
 The DSRW test should be used only for 
 ranking of various materials , not for ab- 
 solute values of wear. For example, a 
 material that wears half as much as 
 another in the test probably will not 
 last twice as long in the field because 
 the test tends to exaggerate differences. 
 Field factors such as the hardness and 
 particle size of the abrading material 
 will affect the absolute values of wear 
 more than they affect the ranking. Typi- 
 cal wear data are presented in table 2. 
 
 Taber Abraser Test 
 
 The Taber Abraser^ is a commercial wear 
 tester designed to test the abrasive 
 wear resistance of flat specimens of a 
 wide variety of materials including coat- 
 ings, paints, metals, plastics, paper, 
 textiles, ceramic tile, and etched or 
 printed material on glass. The wear con- 
 dition can be classified as low-stress, 
 two-body abrasive wear. The model 505 
 Taber Abraser, located at the 
 search Center, can test two 
 simultaneously, a feature useful for rap- 
 idly obtaining duplicate tests or for 
 comparing two materials. 
 
 Taber Abraser Equipment and Specimens 
 
 Wear occurs by the action of a pair of 
 abrasive wheels in contact with the spec- 
 imen. The specimen is rotated at 72 rpa 
 
 •^Reference to specific equipment is 
 made for identification only and does not 
 imply endorsement by the Bureau of Mines. 
 
 Rolla Re- 
 specimens 
 
 TABLE 2. - Typical dry-sand, rubber-wheel abrasive wear data 
 
 Alloy 
 
 Hardness, 
 HB 
 
 Volume loss, mm-' 
 
 
 Procedure A 
 
 Procedure B 
 
 Stainless steel, type 304.. 
 
 156 
 
 408 
 
 160 
 
 Mild steel, AISI 1020 
 
 127 
 
 ND 
 
 133 
 
 Low-alloy steel, ASTM A514. 
 
 269 
 
 ND 
 
 122 
 
 Austenitic 12Mn steel 
 
 197 
 
 ND 
 
 57.1 
 
 Low-alloy steel, AISI 5160. 
 
 280 
 
 ND 
 
 51.3 
 
 Cr white cast iron 
 
 710 
 
 31.5 
 
 12.7 
 
Abrasive 
 
 ■Test specimen 
 
 FIGURE 2. - Taber Abraser test, schematic. 
 
 by a turntable, as shown in figure 2, 
 which causes the abrasive wheels to drag 
 and rotate. The horizontal axis of each 
 abrading wheel is displaced from the ver- 
 tical axis of the test material to pro- 
 duce the abrading motion between wheels 
 and specimen. The abrasive action re- 
 sults in an "X" wear pattern over a 
 ringed area of the specimen (fig. 3). 
 
 Test specimens range from 10 cm square 
 to 16 cm in diam, depending upon the 
 specimen holder. A hole of 6.4 or 9.5 mm 
 is required in the center of most speci- 
 mens. An area of 30 cm^ is exposed to 
 abrasion. The abrading wheels used for a 
 test are selected to provide the desired 
 abrasive quality. Five types of standard 
 abrading wheels and other special wheels 
 are available from the manufacturer. The 
 wheels may contain silicon carbide or 
 alumina abrasives over a range of parti- 
 cle sizes and may be bonded with either 
 rubber or resin. 
 
 Taber Abraser Procedure 
 
 FIGURE 3. - Wear pattern produced by the 
 Taber Abraser. 
 
 A test is conducted by placing the de- 
 sired specimen on the turntable. The 
 desired weight load is placed on the 
 arms carrying the abrasive wheels. Loads 
 of 125, 250, 500, or 1,000 g may be se- 
 lected. The test is run continuously for 
 a prescribed number of revolutions of the 
 specimen: 10, 100, 1,000, or whatever 
 the desired number. The count is dis- 
 played, and the unit will automatically 
 stop at the prescribed count. A vacuum 
 pickup collects abraded particles. 
 
 The test results may be evaluated 
 by four methods , according to the 
 manufacturer: 
 
 1. Visual endpoint method. Certain 
 materials are best evaluated by observing 
 the point at which they undergo a marked 
 change in appearance or break down physi- 
 cally. By this method, the number of 
 test cycles recorded on the counter is 
 a wear index (rate of wear) of the sam- 
 ple. Materials that lend themselves best 
 to this method are plated, glazed, or 
 
polished surfaces; paper; textiles; and 
 fabrics. 
 
 2. Weight-loss method. The weight- 
 loss method of evaluation can be used 
 when test results are compared with those 
 of similar materials with about the same 
 density. In this case, the Taber wear 
 index is the loss of weight in milligrams 
 per thousand cycles of abrasion for a 
 test performed under a specific set of 
 conditions. 
 
 3. Volume-loss method. When comparing 
 the wear loss of materials of different 
 density, it is usual to use the volume 
 loss. The weight loss is converted to 
 volxime loss by dividing by the density of 
 the material. 
 
 4. Depth-of-wear method. It may be 
 desirable after abrasion tests to measure 
 the depth of wear. This can be done with 
 an optical micrometer calibrated in in- 
 crements of one ten-thousandths of an 
 inch. 
 
 Because of the wide variety of materi- 
 als tested, types of abrasive wheels, 
 loads, and revolutions, typical results 
 cannot be reported. For a mild steel us- 
 ing a load of 1,000 g for 1,000 revolu- 
 tions, the weight loss is about 30 to 60 
 mg, depending upon the type of abrasive 
 wheel used. 
 
 Abrasion Resistance Test of 
 Refractory Materials 
 
 The Bureau's abrasion resistance test 
 equipment for refractory materials is lo- 
 cated at the Tuscaloosa Research Center. 
 The equipment and test procedure are de- 
 scribed in ASTM designation C704-76a, en- 
 titled "Standard Method of Test for Abra- 
 sion Resistance of Refractory Materials 
 at Room Temperature" (6^) . The method 
 covers the determination of the resist- 
 ance of refractory brick to a sandblast 
 stream. The test measures the volume of 
 material abraded from a flat surface at 
 a right angle to a nozzle through which 
 1,000 g of size-graded silicon carbide 
 grain is blasted by air at 448 kPa (65 
 
 psi) . The test condition is classified 
 as low-stress, two-body abrasive wear. 
 The condition is considered low-stress 
 because silicon carbide is tougher and 
 more wear-resistant than the refractory 
 brick normally tested. 
 
 A schematic of the test equipment is 
 shown in figure 4. A sandblast gun 
 fitted with a glass nozzle directs the 
 abrasive toward the brick test specimen, 
 which is enclosed in a dust-tight cham- 
 ber. A bag on the vent from the chamber 
 collects the dust. The precision of the 
 test was found by round-robin testing to 
 be ±15 pet. 
 
 Dry-Particle Erosive Wear Test 
 
 Dry-particle erosive wear can be classi- 
 fied as low-stress, two-body wear, the 
 same type as in the preceding test. It 
 simulates the wear conditions that occur 
 in pipes , cyclones , and other equipment 
 that carry fly ash or other particulate 
 matter in a gas stream. A standard prac- 
 tice for conducting a dry-particle ero- 
 sive wear test has been developed by the 
 ASTM G.2 committee on erosion and wear. 
 This practice may be used in the labora- 
 tory to measure the solid-particle ero- 
 sion of different materials and has been 
 used for ranking solid-particle erosion 
 values of materials in simulated service 
 environments (9-11). Actual erosion con- 
 ditions involve particle sizes, veloci- 
 ties , and environments that vary over a 
 wide range (9^) in equipment such as cy- 
 clones, dust collectors, etc. Although 
 one laboratory test cannot simulate the 
 many conditions under which erosion may 
 take place, data obtained over a range of 
 particle velocities and impingement an- 
 gles can help in the selection of wear- 
 resistant materials. 
 
 Dry-Particle Equipment and Specimen 
 
 The essential components of the appara- 
 tus are shown in figure 5. The specimen 
 is mounted in a chamber on a tiltable ta- 
 ble to provide a range of Impingement an- 
 gles . The specimen chamber is shown in 
 figure 6. An abrasive material (normally 
 
50-ym, angular AI2O3) is carried by argon hose through a nozzle that consists of a 
 (or some other gas) through flexible tub- tungsten carbide tube, 1.5 mm in ID by 
 Ing. The gas-solid mixture exits the 50 mm long. The abrasive particles and 
 
 Sand hopper 
 
 A 
 
 Media flow 
 control system 
 
 Sandblast gun 
 
 Dust bag 
 
 Manometer- 
 
 \-/ 
 
 ^ 
 
 ON- OFF 
 valve 
 
 Pressure 
 /"regulator 
 
 HL^ Air 
 
 supply 
 
 Door 
 
 J-^ Nozzle 
 
 \"^ Sample 
 
 FIGURE 4. - Abrasion resistance test of refractory materials, schematic. 
 
/^^ 
 
 Manometer 
 
 3-way valve 
 ^AlgOs+Ar 
 
 Thermometer 
 
 Test chamber 
 
 Abrasive 
 trap 
 
 Nozzle 
 Specimen 
 
 FIGURE 5. • Dry-particle erosive wear test 
 apparatus, schematic. 
 
 gas are mixed and fed by an S. S. White 
 model H Airbrasive unit. Mixing is ac- 
 complished within the Airbrasive unit by 
 feeding particles from a pressurized con- 
 tainer to a mixing chamber mounted on a 
 vibrator. An orifice in the container 
 bottom controls the flow of particles 
 into the gas stream. The particle flux 
 is a function of the voltage applied to 
 the vibrator, and the velocity is a func- 
 tion of the gas stream pressure. The 
 particle velocity is calibrated by a ro- 
 tating double-disk device described by 
 Ruff and Ives ( 12 ) , and particle flux is 
 calculated from the weight of abrasive 
 collected in a given time. 
 
 A novel feature of the Bureau's appa- 
 ratus is its ability to collect the 
 abrasive used during a test run. Other 
 investigators' apparatuses rely on pre- 
 weighing the abrasive or collecting the 
 abrasive during a blank run. In the Bu- 
 reau's apparatus, the abrasive passes 
 from the specimen chamber to a filter 
 where it is collected. A manometer and 
 a thermometer are used to measure the 
 pressure and temperature of the specimen 
 chamber. 
 
 Dry-Particle Procedure 
 
 Particle velocity and flow are measured 
 and adjusted to proper conditions be- 
 fore specimens are tested. The specimens 
 are polished through 400-grit abrasive, 
 cleaned, and weighed to the nearest 0.1 
 mg. After a specimen is mounted in the 
 proper location and orientation in the 
 apparatus, it is subjected to particle 
 impingement for 10 mln. The specimen is 
 then removed, cleaned, and reweighed, and 
 the weight loss is calculated. The spec- 
 imen volume loss is calculated by divid- 
 ing the weight loss by the density of the 
 specimen. The filter and specimen cham- 
 ber are weighed before and after each run 
 to determine the weight of abrasive used. 
 
 Dry-Particle Typical Results 
 
 Table 3 lists some typical test results 
 for the erosive wear of 1020 steel, 304 
 stainless steel, and white cast iron. 
 
 TABLE 3. - Typical dry-particle erosive wear data: 
 per gram abrasive 
 
 erosion loss, 10 
 
 -3 
 
 Impingement 
 
 Mild 
 
 Stainless 
 
 High Cr- 
 
 Impingement 
 
 Mild 
 
 Stainless 
 
 High Cr- 
 
 angle. 
 
 steel, 
 
 steel, 
 
 Mo white 
 
 angle , 
 
 steel. 
 
 steel. 
 
 Mo white 
 
 deg 
 
 AISI 
 1020 
 
 type 304 
 
 cast iron 
 
 deg 
 
 AISI 
 1020 
 
 type 304 
 
 cast iron 
 
 30 m/s: 
 
 
 
 
 70 m/s: 
 
 
 
 
 15 
 
 16.6 
 
 15.1 
 
 7.2 
 
 15 
 
 68.0 
 
 62.3 
 
 48.8 
 
 30 
 
 9.04 
 
 12.3 
 
 15.1 
 
 90 
 
 30.8 
 
 31.8 
 
 43.8 
 
 45 
 
 5.6 
 
 10.9 
 
 12.8 
 
 103 m/s: 
 
 
 
 
 60 
 
 4.3 
 
 9.1 
 
 12.0 
 
 15 
 
 112.9 
 
 101.9 
 
 100.3 
 
 75 
 
 3.3 
 
 7.8 
 
 9.4 
 
 90 
 
 58.7 
 
 55.1 
 
 89.5 
 
 90 
 
 3.14 
 
 4.66 
 
 5.1 
 
 
 
 
 
 NOTE. — 50-wm-diam AI2O3 particles carried by argon, 1.5-mm-diam nozzle. 
 
10 
 
 FIGURE 6. = Dry-particle erosive wear test, specimen chamber. 
 
 The data are expressed as the average 
 volume loss of specimen per gram of abra- 
 sive. The table shows the effect of par- 
 ticle velocity and impingement angle on 
 the wear of the specimens. At all three 
 velocities, the high Cr-Mo white cast 
 iron erodes less than the mild steel and 
 stainless steel at a 15" impingement an- 
 gle but erodes more than the mild steel 
 and stainless steel at 90° impingement. 
 
 Elevated-Temperature , Dry-Particle 
 Erosive Wear Test 
 
 Many industrial materials are subject 
 to high-velocity abrasive particles at 
 elevated temperature. Wear of this type 
 is found, for example, in hot dust 
 
 collection equipment. In order to select 
 and develop materials for high-temper- 
 ature use and to study the basic mecha- 
 nisms of hot erosion, a laboratory test 
 is necessary. Much has been learned 
 about erosion at ambient temperature (10- 
 13 ) , but elevated-temperature work has 
 been very limited. An apparatus suitable 
 for studying hot erosion was designed and 
 constructed by the Bureau. The test con- 
 ditions are similar to those of the 
 dry-particle erosive wear test, just dis- 
 cussed , except that the temperature can 
 be elevated and the atmosphere can be 
 controlled. 
 
 Three elevated-temperature erosion test 
 devices have been reported. Doyle and 
 
11 
 
 Levy ( 14 ) described a device capable of 
 testing specimens from room temperature 
 to 1,000° C with particle velocities 
 ranging from 30 to 180 m/s. The angle of 
 impingement could be varied. The speci- 
 men was heated in a small furnace, and 
 the gas particle mixture was preheated. 
 Young and Ruff (15) described a similar 
 device, except the specimen was heated by 
 passing an electrical current through it. 
 Hansen ( 16 ) described the Bureau's appa- 
 ratus in greater detail. 
 
 Elevated- Temperature Erosive 
 Equipment and Specimens 
 
 The elevated-temperature erosion tester 
 devised by the Bureau is shown sche- 
 matically in figure 7. The apparatus 
 consists of a vessel that contains a 
 multiple-specimen holder on a turret, an 
 electrical resistance heating element, a 
 particle delivery nozzle, a shutter to 
 conrol the abrasive blast duration, ther- 
 mocouples , and an infrared pyrometer to 
 monitor the temperature of the specimen 
 surface within 10° C. The abrasive par- 
 ticles, typically 27-ym AI2O3, are deliv- 
 ered by an Airbrasive unit, as described 
 in the preceding section. The particle 
 delivery nozzle consists of a molybdenum 
 shank about 4 cm long and a 1.3-cm sap- 
 phire tip, 0.058 cm in ID. The multiple- 
 specimen holder accommodates 12 speci- 
 mens, any one of which can be positioned 
 beneath the nozzle during a run. The an- 
 gle of incidence of the particles strik- 
 ing the specimen can be set by placing a 
 wedge under the specimen. A vent in the 
 vessel allows the driving gas to escape. 
 
 Test specimens are approximately 1.5 
 by 1.5 by 0.2 cm. The test surface is 
 ground through 400-grit abrasive. 
 
 Elevated-Temperature Erosive Procedure 
 
 Specimens are cleaned, dried, and 
 weighed before testing. After 12 speci- 
 mens are placed on the turret, the test 
 chamber is sealed, heated in a partial 
 vacuum, and filled with the desired gas, 
 typically nitrogen. About 30 min is 
 required to attain a temperature of 
 700° C. With the shutter closed between 
 the nozzle and the specimen, the particle 
 blast is started. After steady-state 
 conditions are reached, the shutter is 
 opened and the first sample is eroded 
 for the desired time, typically 3 min. 
 The remaining 11 specimens are eroded in 
 the same manner. The furnace is then 
 cooled by a stream of nitrogen gas and 
 the specimens are removed, cleaned, and 
 reweighed. 
 
 Three standard specimens made of Haynes 
 Stellite wrought alloy 6B are run with 
 the nine test specimens in each test. 
 The volume loss of each specimen is cal- 
 culated from its weight loss and density. 
 The data are reported as the ratio of 
 volume loss to the average volume loss 
 for the three Stellite standard speci- 
 mens. This ratio is referred to as the 
 relative erosion factor (REF) . 
 
 Elevated-Temperature Erosive Results 
 
 Table 4 contains erosion data for sev- 
 eral materials tested at 700° C using 
 
 TABLE 4. - Hot erosive wear of several materials 
 
 Material 
 
 Nominal composition, wt pet 
 
 Relative erosion factor 
 
 MgAl oxide 
 
 Co-based hardf acing 
 
 Do 
 
 Stainless steel, type 304... 
 Stainless steel, type 316... 
 
 SiC, hot pressed 
 
 B4C, hot pressed 
 
 Si3N4, hot pressed 
 
 97MgAl204-3MgO , 
 
 Co-31Cr-12.5W-2.4C , 
 
 Co-30Cr-4.5W-1.5Mo-1.2C 
 
 Fe-17Cr-9Ni-2Mn-lSi 
 
 Fe-17Cr-12Ni-2Mn-lSi-2.5Mo, 
 
 NAp , 
 
 NAp , 
 
 NAp , 
 
 2.76 
 1.61 
 1.00 
 .73 
 .56 
 .44 
 .21 
 .12 
 
 NAp Not applicable. 
 
 NOTE. — 700° C, 90° impingement, 27-ym AI2O3 particles, 5-g/min particle flow, 170- 
 m/s particle velocity, 3-min test duration, N2 atmosphere. 
 
12 
 
 Turret drive 
 
 Turret lock 
 
 Pyrometer port 
 Gas and abrasive inlet 
 
 Insulation 
 
 FIGURE 7. - Elevated-temperature erosion tester, schematic. 
 
 nitrogen gas and 27-yni AI2O3 particles at 
 90° impingement. The data reflect the 
 average values for a set of five tests. 
 One standard deviation of a set of tests 
 was typically within 10 pet of the mean. 
 The data reported include a wide range of 
 REF values. 
 
 Low-Angle Slurry Pot Test 
 
 Transporting minerals as a slurry is 
 an efficient means of transportation and 
 is done during many mineral beneficia- 
 tion processes. However, the movement of 
 slurries can cause significant wear to 
 
13 
 
 the slurry-handling equipment, especially 
 in places where the flow changes direc- 
 tion. Wear caused by slurries is an eco- 
 nomic concern of industry. Pumps, el- 
 bows, tee junctions, and hydrocyclones 
 are component parts of slurry transport 
 systems that are exposed to severe wear. 
 In a slurry, abrasive erosion is produced 
 by the solid particles, and corrosion may 
 be produced by the liquid; the two are 
 frequently synergistic. Reliable experi- 
 mental wear data are needed to aid in the 
 design of slurry transport equipment. 
 
 Types of slurry wear tests reported in 
 the literature include slurry pot, pipe- 
 line, and jet impingement. All of these 
 involve low-stress, two-body abrasive 
 wear. Many variations of a slurry pot 
 test have been devised. Jackson (17) 
 used a rotating wire, Tsai ( 18) used two 
 rotating metal tubes, and Bess ( 19 ) used 
 a rotating disk as specimens in baffled 
 pots containing abrasive slurries. These 
 slurry pot tests relied on experimen- 
 tal reproducibility because only one type 
 of specimen was used in any one test. In 
 addition, the impingment velocity was 
 based on the assumption that baffles in 
 the pot held the slurry stationary. 
 Postlethwaite (20) , Hocke and Wilkinson 
 (21), and Elkholy ( 22 ) used closed-loop 
 slurry pipeline test systems. Postle- 
 thwaite used rectangular specimens that 
 were flush with the inside wall of the 
 pipeline, and Hocke used rectangular 
 specimens with a slurry jet impingement 
 tester. All of the above-mentioned slur- 
 ry wear tests have the problems of 
 abrasive particle degradation and slurry 
 contamination by wear debris. These 
 problems are inherent in tests that re- 
 circulate the slurry for prolonged times. 
 The low-angle slurry pot test devised by 
 the Bureau is normally operated in a 
 flowthrough mode that essentially elimi- 
 nates the problems of particle degrada- 
 tion and slurry contamination. 
 
 Slurry Pot Equipment and Specimens 
 
 The Bureau's slurry test apparatus is a 
 slurry pot consisting of an impeller that 
 rotates the slurry past an array of 
 
 specimens located around the inside of 
 the pot. Thus, the impingement angle is 
 low or nearly tangential. A schematic of 
 the equipment is shown in figure 8. The 
 slurry pot consists of a plastic ring 
 with 16 sides that form a hexadecagon to 
 hold specimens. This central section is 
 bolted to a stainless steel top and bot- 
 tom and is sealed with 0-rings. In order 
 to avoid galvanic effects between unlike 
 specimens , eight specimens are alternated 
 with eight plastic inserts around the in- 
 side of the plastic ring. Both the spec- 
 imens and plastic inserts are 24 by 32 mm 
 and 10 mm thick. The plastic inserts are 
 made of ultrahigh-molecular-weight poly- 
 ethelene, which has proven very wear re- 
 sistant. The ends of the specimens are 
 beveled to fit adjacently inside the 
 plastic ring. The test surface of the 
 specimen is surface-ground and polished 
 through 400-grit abrasive before each 
 test. 
 
 The impeller is made from a commer- 
 cial helical gear made of hardened steel 
 that rotates to move the slurry past the 
 stationary specimens. Dry sand is fed 
 through a nozzle to a slurry hopper where 
 the sand is mixed with the liquid. In 
 tests conducted with this flowthrough 
 system, typically, tapwater is fed to the 
 system at a rate of 4.34 L/min and the 
 sand is fed at 88 g/min, which results in 
 a mean retention time for the sand in the 
 slurry pot of only 2 s. The slurry dis- 
 charges to a settling basin where the 
 solids settle and the water flows to a 
 drain. A modified drill press supports 
 the slurry pot and drives the helical 
 gear. A magnetic pickup provides a means 
 to electronically measure the impeller 
 tip speed, which can be varied from 1.3 
 to 22.4 m/s by changing the belt system 
 in the drill press. The temperature of 
 the slurry is monitored at the discharge 
 of the slurry pot. The equipment is il- 
 lustrated in figure 9. 
 
 Alternatively, the slurry can be recir- 
 culated by shifting the slurry discharge 
 back into the slurry hopper, as shown in 
 figure 8. This alternate mode can be 
 used to study the changes in particle 
 
14 
 
 Liquid 
 supply 
 
 Slurry 
 hopper 
 
 Dry abrasive hopper 
 
 Abrasive nozzle 
 
 Liquid 
 overflow 
 
 ^::) 
 
 o 
 
 Impeller 
 
 ^^^ y^>\ \,\ ^x\\\\\\\x\\\\\\^ 
 
 Alternate circuit 
 for recycled slurry 
 test 
 
 Slurry 
 
 ^m m^m 
 
 flow 
 
 Rectangular 
 specimen 
 
 Specimen 
 holder 
 
 Circuit for 
 flow-through 
 slurry test 
 
 Pump 
 
 FIGURE 8. - Low-angle slurry pot equipment, schematic. 
 
 Slurry 
 recovery 
 
15 
 
 FIGURE 9. - Low-angle slurry pot test equipment. 
 
16 
 
 shape and roughness and their effect on 
 wear rates. Tests such as these also can 
 be used to characterize wear mechanisms . 
 
 Slurry Pot Procedure 
 
 Specimens are prepared for testing by 
 cleaning, drying, and weighing to the 
 nearest 0.1 mg. Up to eight specimens 
 along with the plastic inserts are placed 
 inside the plastic center ring. Replace- 
 able inserts above and below the speci- 
 mens ensure that the specimens are elec- 
 trically insulated from the stainless 
 steel top and bottom sections. 
 
 The mass flow rates of the dry abra- 
 sive solids and the solution are each 
 adjusted prior to the test to provide 
 the desired percent solids and slurry 
 flow rate. After the solution is pumped 
 through the system for a few seconds , the 
 helical gear and sand flow are started, 
 and the time is noted. After a predeter- 
 mined test time, the slurry pump and hel- 
 ical gear are stopped, and the samples 
 are removed, cleaned, dried, and weighed. 
 The specimens are put back into the slur- 
 ry pot, and the test is repeated sev- 
 eral times. The volume losses are calcu- 
 lated and recorded as a function of time. 
 Curves of time versus volume loss are 
 then compared with data obtained with 
 standard AISI A514 steel specimens. The 
 test procedure in the recirculating mode 
 is essentially the same, except the per- 
 cent solids is determined by the initial 
 mass of solids and solution put into the 
 system. 
 
 One of the attributes of the flow- 
 through system is that the temperature of 
 the slurry is nearly constant and is de- 
 termined by the temperature of the liquid 
 supply. When recycled slurry is used, a 
 means of heat exchange at the slurry hop- 
 per is required to prevent overheating of 
 the system. 
 
 Specimens can be reused after regrind- 
 ing and repolishing the wear surface and 
 regrinding one beveled edge. Plastic 
 inserts are placed behind the reground 
 specimens in order to maintain the same 
 clearance between the rotating gear and 
 the specimen surface. This assures the 
 same geometry inside the pot and gives a 
 constant exposed area of wear surface. 
 The size of the specimens allows two to 
 be made from each previously worn speci- 
 men from dry-sand, rubber-wheel abrasive 
 wear tests or jaw crusher tests. 
 
 Slurry Pot Results 
 
 Typical results of wear testing with 
 the low-angle slurry pot are presented in 
 table 5 for both flowthrough and recy- 
 cled slurry tests. Results of the flow- 
 through tests showed that the wear rate 
 is constant with respect to time. In 
 contrast, conventional slurry tests that 
 use a recycled slurry give decreasing 
 wear rates with time (17-22) . In addi- 
 tion, table 5 shows that lower wear rates 
 were obtained with recycled silica sand. 
 The lower wear rates result from the 
 rounding of the slurry particles during 
 the test. The ranking of specimens with 
 
 TABLE 5. - Typical low-angle slurry wear data for several 
 metallic specimens: wear rate, cubic millimeter per hour 
 
 Specimen type 
 
 Flowthrough 
 slurry 
 
 Recycled slurry 
 
 0.33 h 
 
 0.67 h 
 
 1 h 
 
 Stainless steel, type 304. 
 Low-alloy steel, ASTM A514 
 Mild steel plus 2 pet Si.. 
 Low-alloy steel, AISI 4342 
 
 Ni-based hardf acing 
 
 Co-based hardfacing. ...... 
 
 22.1 
 21.1 
 21.2 
 6.99 
 3.56 
 2.40 
 
 12.1 
 6.10 
 5.42 
 1.60 
 1.36 
 1.46 
 
 4.85 
 2.54 
 .274 
 .028 
 .778 
 .163 
 
 1.94 
 1.06 
 .014 
 .001 
 .444 
 .018 
 
 NOTE. — Water with 2-pct silica sand (minus 50 plus 70 mesh), 
 17° C, 15.7 m/s. 
 
17 
 
 respect to wear rate also can change dur- 
 ing a recycled slurry test. For exam- 
 ple, after 1 h, the fifth specimen had 
 a greater wear rate than the fourth 
 specimen. 
 
 Jaw Crusher Gouging Abrasion Test 
 
 Gouging wear occurs in many mining op- 
 erations, for example, where excavator 
 teeth or loaders penetrate or drag over 
 rock, and in jaw and gyratory crushers. 
 Gouging wear is identified by the removal 
 of a significant amount of material (a 
 gouge) from the wear object after an en- 
 counter by the abrasive object in which 
 the abrasive object also suffers damage. 
 It is a type of high-stress wear that may 
 be produced by either two-body or three- 
 body conditions. The jaw crusher test 
 gives high-stress, three-body abrasive 
 wear. Jaw crusher wear tests were pio- 
 neered in the United States by Borik (23- 
 24) , improved by Fuller, ^ and used abroad 
 by Sare and Hall (25). The jaws that 
 crush the rock are taken as the test 
 specimen. Several investigators believe 
 that the jaw crusher test gives the 
 closest correlation to wear that occurs 
 on earth-penetrating equipment, such as 
 excavator teeth, power shovel buckets, 
 scoops, and grader blades, as well as 
 real jaw crusher wear. ASTM committee 
 G.2 has developed a new standard prac- 
 tice for the jaw crusher gouging abrasion 
 test. 
 
 The Bureau's jaw crusher test equip- 
 ment is considerably smaller than any re- 
 ported in the literature. The smaller 
 size gives greater economy of rock con- 
 sumed and smaller specimen size. Typical 
 values for the Bureau's test con^jared 
 with typical values used in previous 
 tests are — rock consumed, 91 kg versus 
 910 kg; specimen size, 1 by 2.5 by 7 cm 
 versus 2 by 7 by 15 cm; and specimen 
 weighing precision, ±1 mg versus ±100 mg. 
 
 ^Fuller, W. (Esco Corp., Portland, OR). 
 Private communication. 
 
 Jaw Crusher Equipment and Specimen 
 
 A small commercial laboratory jaw 
 crusher was modified to accept an easily 
 machined, identical pair of test wear 
 plates and a similar pair of reference 
 wear plates . One test plate and one ref- 
 erence plate are attached to the station- 
 ary jaw, and the other test and reference 
 plates are attached to the movable jaw, 
 such that a test plate and a reference 
 plate oppose one another. A rock hopper 
 and rock chute are attached above the 
 jaw crusher. The arrangement of the jaw 
 crusher test equipment is shown in fig- 
 ure 10, and a photograph is presented in 
 figure 11. The jaw crusher operates at 
 260 c/min. 
 
 The jaw crusher was extensively rebuilt 
 and strengthened in order to transform it 
 from a crude laboratory crusher into a 
 precision wear test apparatus. The jaw 
 opening, originally 7.5 cm (3 in) wide, 
 was reduced to 5 cm (2 in) , thus pro- 
 viding a specimen width of 2.5 cm (1 in). 
 An alloy steel eccentric shaft of larger 
 diameter was made, heattreated, and 
 fitted with needle bearings. New bearing 
 blocks were made and welded to reinforced 
 side plates. New jaws that would hold 
 test specimens were made, and the jaw 
 opening adjuster was redesigned and re- 
 built. The original 1.1-kW drive motor 
 was replaced with a 3.7-kW motor. Be- 
 cause of the many modifications, it is 
 recommended that anyone wanting a jaw 
 crusher test machine should design and 
 construct a completely new unit instead 
 of rebuilding an existing jaw crusher. 
 
 The test wear plates and reference wear 
 plates have a 15° taper on each end for 
 clamping to the jaws. All specimen 
 surfaces are machined on a surface 
 grinder. The small size of the specimens 
 has a distinct advantage because previ- 
 ously used specimens from dry-sand, 
 rubber-wheel abrasion tests can be used 
 in the jaw crusher after regrinding. The 
 standard reference material used is a 
 
18 
 
 Sliding gate 
 
 Movable jaw 
 Fixed jaw 
 
 Specimens 
 
 Roller bearings on 
 eccentric shaft 
 
 Motor 
 
 -Toggle 
 
 FIGURE 10. - Jaw crusher gouging wear test machine, schematic. 
 
 low-alloy steel, ASTM A514, 
 ell hardness of HB 269. 
 
 with a Brin- 
 
 The test gives wear of a test material 
 relative to a standard steel. Because 
 the test is relative, variables in the 
 rock have little effect on test results. 
 Therefore, the size distribution and min- 
 eral composition of the rock are not 
 specified. 
 
 Jaw Crusher Procedure 
 
 After the four wear plates are cleaned 
 and weighed to ±1 mg, they are clamped to 
 the jaws with a standard plate opposing a 
 test plate. The minimum jaw opening is 
 set to 3.18 mm (0.125 in), and a 45-kg 
 load of prescreened rock, minus 2 cm 
 (3/4 in), is run through the crusher. 
 The minimum opening is reset to 3.18 mm, 
 and another 45 kg of rock is crushed. 
 The specimens are recleaned by vigorous 
 scrubbing with a bristle brush. The 
 volume loss may be calculated from the 
 
 mass loss, determined by weighing, and 
 the known densities of the test materi- 
 als. A wear ratio is developed by divid- 
 ing the volume loss of the test plate by 
 the volume loss of the reference plate. 
 This is done separately for the station- 
 ary and movable plates. The two wear ra- 
 tios are then averaged for a final test 
 ratio. The smaller the figure for the 
 wear ratio, the better the wear resist- 
 ance of the test plate. 
 
 Jaw Crusher Typical Results 
 
 After crushing 90 kg of rock, the typi- 
 cal weight loss of the standard steel 
 specimen was 0.4 g on the fixed jaw and 5 
 g on the movable jaw. The wear ratios of 
 test specimen to standard steel are given 
 for several materials in table 6. Tests 
 on materials having greater abrasive wear 
 resistance than the standard gave wear 
 ratios less than 1. For example, hard- 
 ened AISI 4340 steel gave a wear ratio of 
 0.157, and a high Cr-Mo white cast iron. 
 
19 
 
 FIGURE n. • Jaw crusher gouging wear test machine. 
 
20 
 
 TABLE 6. - Typical jaw crusher gouging wear data 
 
 Alloy 
 
 Hardness, 
 HB 
 
 Wear ratio 
 
 Low-alloy steel, ASTMA514.... 
 Austenitic 12Mii steel. ........ 
 
 269 
 187 
 603 
 588 
 555 
 
 1.000 ±0.030 
 .284 
 
 Low-alloy steel, AISI 4340 
 
 6Ni-8Cr white cast iron 
 
 High Cr-Mo white cast iron.... 
 
 .157 
 .134 
 .0823 
 
 NOTE. — Minimum jaw opening set at 3.18 mm (0.125 in); 
 standard jaw of A514 steel, HB 269; 90 kg (200 lb) of 
 rock crushed. 
 
 known for its superior abrasive wear re- 
 sistance, gave a wear ratio of 0.0823. 
 
 The precision of the jaw crusher is de- 
 termined after every six test runs. This 
 is done by making a run in which all four 
 specimens are of the standard steel. The 
 average wear ratio of the two pairs of 
 specimens must be 1.000±0.030, according 
 to ASTM recommendations on the jaw crush- 
 er test. The average ratio for the Bu- 
 reau's tests fell within this limit. 
 
 Ball Mill Wear Test 
 
 When a lump of ore is crushed by the im- 
 pact between two balls in a ball mill, 
 it is considered high-stress, three-body 
 abrasive wear. The abrasive wear of 
 balls that results from the milling of 
 ore is the major wear loss in most miner- 
 als processing plants. During the wet 
 milling of ores , abrasive wear is com- 
 bined with corrosion. Abrasion and cor- 
 rosion are synergistic: a corroded sur- 
 face is more easily abraded than an 
 abraded surface and an abraded surface is 
 more easily corroded than a corroded pas- 
 sivated surface. Thus, each enhances the 
 other. Natarajan ( 26 ) showed that abra- 
 sive wear loss was much greater than cor- 
 rosion loss on steel balls during the 
 laboratory ball milling of magnetic tac- 
 onite. Bond ( 27 ) reported that wear 
 rates during grinding became extreme as 
 the pH of the liquid dropped below 5.5. 
 Ellis ( 28 ) did extensive tests on the ef- 
 fect of pH and atmosphere on steel balls 
 while wet grinding sand in small 0.3- and 
 1-m-diam mills. Norman and Loeb (29) 
 
 extended the work to include the grinding 
 of molybdenum ore in 3-m-diam mills. 
 
 The Bureau set up an apparatus to study 
 wear caused by erosion-corrosion of spe- 
 cific ores and liquids. Two sizes of 
 mills are used, a small mill, 12 cm ID, 
 and a larger mill, 60 cm ID. The smaller 
 mill is more convenient for laboratory 
 research, but the surface of the test 
 specimens may passivate because the small 
 impacts may not significantly abrade the 
 protective layer. That is, synergism may 
 not occur. The larger mill assures more 
 aggressive abrasion that is closer to the 
 conditions in commercial mills. 
 
 Ball Mill Equipment and Specimens 
 
 The small ball mill is a commercial 12- 
 cm-diam porcelain mill with five silicone 
 rubber lifters added inside. The drive 
 rotates the mill at 120 rpm. Figure 12 
 shows the mill with typical specimens, 
 rock, and liquid for a run. 
 
 The larger ball mill (fig. 13) , is 60 
 cm in diam by 20 cm long. It was fabri- 
 cated from steel and lined with natural 
 rubber, 1 cm thick. The interior of the 
 mill has 12 lifters, each 2 cm high. In 
 operation, the mill is entirely closed 
 except for a vent in the center to pre- 
 vent buildup of gas pressure. One end of 
 the mill can be unbolted and removed for 
 loading specimens, rock, and liquid. The 
 mill is rotated by two rollers driven by 
 a 2.7-kW motor that drives the mill at 
 43 rpm or 75 pet of critical speed. A 
 wooden cover fits over the mill and drive 
 
21 
 
 FIGURE 12. - Small ball mill with specimens, 
 liquid, and ;ocI<. 
 
 Drum, 60-cm diam 
 
 Thermostat 
 
 FIGURE 13.- Ball mill test equipment, schematic. 
 
 assembly. A heater and thermostat within 
 maintain constant temperature during a 
 run. 
 
 The specimens used in the small ball 
 mill are oblate spheroids about 2 cm in 
 diam by 1 cm thick. Specimens of a wide 
 
 range of alloys are conveniently prepared 
 in an inert atmosphere box by arc-melting 
 the starting materials on a copper hearth 
 plate. The surface finish of such speci- 
 mens is relatively smooth and requires 
 little or no further grinding before 
 testing. 
 
 The test specimens used in the larger 
 mill are cylinders , 5 cm in diam by 5 cm 
 long, that are conveniently made by 
 cutting commercial 5-cm rods into 5-cm 
 lengths. Noncommercial alloys are made 
 by casting in a sand mold. The cast 
 specimens are sandblasted and rough 
 ground. 
 
 Ball Mill Procedure 
 
 To conduct a test in either ball mill, 
 specific amounts of liquid and ore or 
 rock are selected to provide a slurry. 
 The ratio of ore weight to total surface 
 area of the specimens is kept the same in 
 both mills for comparison of results. 
 Typically, 1.13 L of liquid, 3.8 L of 
 ore, and six specimens are used in the 
 larger ball mill. Test specimens are 
 cleaned, dried, and weighed. The ore is 
 put into the mill and is warmed to the 
 desired operating temperature, normally 
 35° C. The test specimens and liquid are 
 added to the ore, and the temperature and 
 pH are measured. The mill is then sealed 
 and run at constant temperature. After 1 
 h of running time, the mill is opened, 
 the temperature of the slurry is mea- 
 sured, and the specimens are removed 
 and cleaned with water and a soft nylon 
 brush. A sample of the slurry is fil- 
 tered, and the pH is measured. The tests 
 on a given material are repeated until 
 a consistent trend in weight loss is ob- 
 tained. The surface area of each speci- 
 men is determined, and from the density 
 and mass loss during the test time, the 
 erosion-corrosion rate in mils per year 
 (1 mil = 0.001 in) is calculated. 
 
 Ball Mill Results and Discussion 
 
 A study of erosion-corrosion of grind- 
 ing media during the grinding of Florida 
 phosphate rock with recycled waste phos- 
 phoric acid showed some characteristics 
 
22 
 
 of the two ball mills. This slurry was 
 quite acidic, ranging from an initial pH 
 of 2 to a final pH of 3 after the 1-h 
 test. Erosion-corrosion wear data on 
 four alloys are given in table 7. Cor- 
 rosion-resistant materials , the nickel- 
 base alloy, Hastelloy C-276, and the 
 stainless steel, type 316, had good wear 
 resistance in the small ball mill where 
 impacts were small. In the large ball 
 mill, however, the wear rate increased 
 about 10 times. Apparently the larger 
 mill produced impacts sufficient to re- 
 move the passivated film, thereby allow- 
 ing an erosion-corrosion synergism. The 
 data show that the large ball mill should 
 give a more accurate correlation with in- 
 dustrial wet-grinding mills. 
 
 TABLE 7. - Ball mill erosion-corrosion 
 of several materials , using phosphate 
 rock and waste phosphoric acid, 
 mils per year 
 
 Alloy 
 
 13-cm 
 
 60-cm 
 
 
 mill 
 
 mill 
 
 Ni-Cr white cast iron 
 
 2,590 
 
 1,930 
 
 High-C steel, AISI 1090.... 
 
 2,240 
 
 1,420 
 
 Stainless steel, type 316.. 
 
 118 
 
 1,090 
 
 Ni alloy, Hastelloy C-276.. 
 
 47 
 
 559 
 
 Pin-on-Drum Abrasive Wear Test 
 
 The pin-on-drum abrasive wear test in- 
 volves high-stress, two-body abrasive 
 wear. One end of a cylindrical pin spec- 
 imen is moved over an abrasive paper, 
 abrading material from the specimen and 
 crushing the fixed abrasive grains. The 
 wear is believed to simulate wear that 
 occurs during crushing and grinding of 
 ore — processes in which the abrasive par- 
 ticles are crushed, therefore called 
 high-stress abrasive wear. 
 
 Considerable pin-abrasive wear testing 
 has been conducted on pin-on-disk equip- 
 ment, beginning with Robin's machine in 
 1910 (30). This machine wore a pin sam- 
 ple along a single track on the surface 
 of an abrasive cloth fixed to the flat 
 surface of a disk. Khruschov made a ma- 
 jor improvement by making the pin follow 
 a spiral path, like a phonograph, to 
 
 always encounter fresh abrasive. The 
 work on this type of machine, reviewed by 
 Moore (31), helped establish the effect 
 of many parameters , such as abrasive 
 material and size, specimen load, and 
 speed, on two-body abrasion. Climax 
 Molybdenum Co. developed a pin-on-table 
 machine ( 32 ) with several improvements 
 over the pin-on-disk machine. Using a 
 converted milling machine, the moving ta- 
 ble with abrasive attached provided a 
 constant surface speed. The test speci- 
 men was rotated to abrade the pin surface 
 from all directions. Using the operating 
 parameters from the Climax machine. Mut- 
 ton (33-34) at Melbourne Research Labora- 
 tories developed a pin-on-drum abrasion 
 machine in which a slowly rotating drum 
 was substituted for the moving table. 
 The Bureau's machine is very similar to 
 the Melbourne machine except for a few 
 minor refinements. These latter three 
 machines all can use the same type of 
 abrasive, path length, load, speed of 
 abrasive, and rotational speed of the 
 specimen. 
 
 Pin-on-Drum Equipment and Specimen 
 
 The equipment consists of a head that 
 rotates the test specimen while travers- 
 ing the length of a cylindrial surface of 
 a rotating drum covered with abrasive pa- 
 per (figs. 14-15). The head has three 
 functions. First, it loads the specimen. 
 Second, it translates the specimen slowly 
 along the drum so that only fresh abra- 
 sive is encountered. Third, it rotates 
 the test specimen to produce wear scars 
 in all directions across the end of the 
 specimen. The applied load is normally 
 66.7 N. The 0.5-m-diam drum is covered 
 with abrasive cloth, either AI2O3, SiC, 
 or garnet of the desired size, usually 
 120 to 150 mesh. The abrasive cloth is 
 obtained in rolls, 61 cm wide, from a 
 commercial source. During operation, the 
 pin traverses 12.7 mm parallel to the 
 axis of the drum while the drum makes 
 one revolution. The wear path is 1.6 m 
 per drum revolution. The drum rotates at 
 1.7 rpm to give a surface speed of 2.7 
 m/min. The pin specimen rotates at 17 
 rpm. Through a system of gearing, a 
 
23 
 
 FIGURE 14. = Pin-on»drum abrasive wear test machine, schematic. 
 
 single motor drives the entire machine, 
 which automatically stops after complet- 
 ing a preset number of drum revolutions. 
 A gear-dlsengaglng mechanism allows repo- 
 sitioning of the specimen at intervals of 
 6.35 mm along the drum. 
 
 The test specimen consists of a pin 
 6.35 mm in diam by 2 to 3 cm long. Spec- 
 imens are normally prepared by machining 
 in a lathe; hard or brittle metal speci- 
 mens are cut out by electrodlscharge 
 machining and then are finish ground 
 in a lathe. Specimens over a wide range 
 of hardness, including soft magnesium 
 and hardened white cast iron, have been 
 evaluated. 
 
 Pln-on-Drum Procedure 
 
 A new test specimen is worn in for ap- 
 proximately four revolutions, or until 
 its entire end displays wear scars, be- 
 fore beginning the test runs. The test 
 of a material requires two runs — one on 
 the test specimen and one on a standard 
 specimen. The number of drum revolutions 
 is chosen to provide a reasonable amount 
 of wear, that is, about a 40-mg loss. 
 This requires about 6 revolutions (9.6-m 
 path) for soft materials and 12 or more 
 revolutions for hard materials. After 
 the test specimen has been run, the stan- 
 dard specimen is run for the same num- 
 ber of drum revolutions with its track 
 
24 
 
 where 
 
 FIGURE 15. » Pinion-drum abrasive wear test machine. 
 
 exactly between the tracks left by the 
 test specimen. The standard material is 
 a low-alloy steel, ASTM A514, with a 
 hardness of HB 269. The standard speci- 
 men wear is used to correct for small 
 variations in the abrasiveness of the 
 abrasive cloth from lot to lot and within 
 a given lot. 
 
 W is the corrected mass loss of 
 the test specimen per meter 
 of path length, 
 
 W^ is the measured mass loss of 
 the test specimen for x num- 
 ber of revolutions , 
 
 S^ is the 
 
 measured mass loss of 
 the standard specimen for the 
 same x number of revolutions , 
 
 and 
 
 is the long-term average mass 
 loss of the standard specimen 
 per drum revolution. 
 
 Specimens are cleaned ultrasonically in 
 water with detergent, rinsed in water, 
 rinsed in alcohol, and air-dried before 
 each weighing. 
 
 Test materials of approximately the 
 same density, such as irons and steels, 
 can be compared by weight loss. Materi- 
 als of differing density should be com- 
 pared by volume loss. Thus, the wear is 
 reported as cubic millimeters (volume 
 loss) per meter (path length) for a 66.7- 
 N load on the given abrasive. 
 
 Pin-on-Drum Results and Discussion 
 
 The corrected mass loss of a test spec- 
 imen for a given abrasive type under a 
 given load is 
 
 W = 
 
 1.6S, 
 
 This test apparatus has proven useful 
 in ranking a wide range of materials 
 under the conditions of two-body, high- 
 stress wear. Table 8 shows typical re- 
 sults for a variety of materials, using 
 
 TABLE 8. - Typical pin-on-drum wear test data 
 
 Alloy 1 
 
 Hardness , 
 HB 
 
 Wear loss, mm^/m 
 
 
 120-grit AI2O3 
 
 150-grit garnet 
 
 Pure iron 
 
 61 
 127 
 
 1.70 
 1.67 
 
 1.86 
 
 Mild steel, AISI 1020 
 
 1.52 
 
 Low-alloy steel, AISI 8620.. 
 
 176 
 
 1.28 
 
 1.35 
 
 Low-alloy steel, ASTMA514.. 
 
 269 
 
 1.225 
 
 1.29 
 
 Low-alloy steel, AISI 4142.. 
 
 200 
 
 1.035 
 
 1.124 
 
 Low-alloy steel, AISI 5160.. 
 
 280 
 
 1.009 
 
 1.054 
 
 High-C steel, AISI 52100.... 
 
 322 
 
 .793 
 
 .790 
 
 Cr white cast iron 
 
 410 
 
 .446 
 
 .267 
 
 'Steels were in hot-worked condition; cast iron was 
 condition. 
 
 in as-cast 
 
 NOTE. — 66.7-N load, 6.4-mm-diam pin. 
 
25 
 
 AI2O3 and garnet abrasive cloth. The 
 garnet gives a greater spread in wear 
 values. The results show that wear on 
 pure iron can be reduced to about one- 
 half by alloying to form steel and to 
 about one-fourth by alloying to make 
 white cast iron. 
 
 The reproducibility of the test has 
 been very good. In repeating a test im- 
 mediately, the coefficient of variation 
 has been less than 2 pet. Results on ma- 
 terials retested after several months' 
 time with a different lot of abrasive 
 cloth differed by less than 5 pet from 
 the earlier results. 
 
 A set of 12 specimens was used to com- 
 pare wear on the Bureau's machine with 
 wear on the pin-on-table test of Climax 
 Molybdenum Co. The results gave very 
 nearly the same ranking of materials, but 
 the wear on the Climax machine was con- 
 sistently about 11 pet less for the same 
 load, path length, and abrasive type. 
 
 High-Speed Impact-Gouging Test 
 
 A new and promising method for trans- 
 porting raw materials from a mine is by 
 pneumatic pipeline. This method uses a 
 flow of air to transport solid particles 
 of rock or ore through a pipeline. Lift- 
 ing ore from underground to the surface 
 pneumatically has great economic poten- 
 tial but is limited by severe wear prob- 
 lems. Pneumatic conveying is currently 
 used for backfilling underground mines 
 and trenches, removing tunnel muck, and 
 transporting coal and ores within an un- 
 derground mine. 
 
 During pneumatic transport, severe wear 
 at pipe bends is caused by collision of 
 solid particles with the interior of the 
 pipe. The particles may be as large as 6 
 to 10 cm across, traveling at speeds up 
 to '40 m/s. Elbows have been known to 
 wear through after only a few hours of 
 use. A limited amount of research has 
 been done to evaluate the erosive wear of 
 bends used in pneumatic transport. Mills 
 and Mason (35-38) used a closed-loop ex- 
 perimental apparatus to simultaneously 
 
 determine the wear rates of six pipe 
 bends. Kostka ( 39 ) used coarse solid 
 particles in a commercial-sized pneumatic 
 transport system to study erosive wear in 
 different types of pipe bends. 
 
 No prior experimental apparatus has 
 been developed to study the effect of 
 high-impact abrasive wear caused by large 
 particles with a mass greater than a few 
 grams . The Bureau has designed and con- 
 structed test equipment capable of shoot- 
 ing a 1-kg projectile at a test specimen 
 at speeds up to 45 m/s. The test has 
 been named the high-speed impact-gouging 
 test. The wear condition is classified 
 as high-stress, two-body abrasive wear. 
 The condition is considered high-stress 
 because the abrasive projectile suffers 
 appreciable damage during impact. 
 
 High-Speed Impact Equipment 
 and Specimen 
 
 The test equipment consists of an air 
 gun that shoots rock projectiles at a 
 stationary specimen located a short dis- 
 tance from the muzzle. The specimen 
 stage can be tilted to vary the angle be- 
 tween the projectile line of flight and 
 the specimen surface. The test equipment 
 is shown in figures 16 and 17. The pro- 
 jectile is a cylinder 7 cm in diam by 10 
 cm long, weighing 1 kg. Solid granite 
 cores can be used, but for economy, a 
 concrete cylinder with a granite disk 
 about 2 cm thick on the impact end is 
 used. A pin through the side of the tube 
 holds the projectile in place while driv- 
 ing gas is admitted to give the desired 
 pressure. A chronograph is used to de- 
 termine the velocity of the projectile 
 after it exits the tube. A box below 
 the impact area collects debris from the 
 shattered projectiles, and a safety 
 shield covers the end of the tube and the 
 impact area. 
 
 The test specimens are normally 7.6 
 by 2.5 by 1.3 cm, with beveled ends for 
 clamping. They are interchangeable with 
 the jaw crusher test specimens previously 
 described. 
 
26 
 
 o 
 
 Gas-pressure 
 controls 
 
 Oscilloscope timer 
 
 FIGURE 16. - High-speed impact-gouging test machine, schematic. 
 
 High-Speed Impact Procedure 
 
 The specimens are cleaned, dried, and 
 mounted on the target face, with the an- 
 gle of incidence set by adjusting and 
 locking the target. The tube is cleaned 
 and sprayed with a Teflon fluorocarbon 
 polymer coating that lowers friction and 
 wear. The projectile is loaded into the 
 tube, a rubber seal is placed behind the 
 projectile, and the breech is closed. 
 Gas is admitted to the chamber to a spe- 
 cified pressure, the chronograph is set, 
 and the projectile is released by actuat- 
 ing the solenoid that retracts the re- 
 taining pin. 
 
 After the projectile is shot, the time 
 recorded by the oscilloscope is noted and 
 used to calculate the projectile veloc- 
 ity. The target specimen is removed, 
 cleaned with a brush, and soaked in con- 
 centrated hydrofluoric acid in order to 
 remove the embedded silicate material. 
 
 The specimen is then dried and weighed. 
 The barrel is cleaned for the next run. 
 
 Although the test equipment is rela- 
 tively new, several general findings can 
 be reported. Examination of the specimen 
 surfaces of mild steel after impact has 
 revealed gouges resulting from ductile 
 deformation. The gouge scars are much 
 deeper but shorter at a 45° angle of im- 
 pact than at a 15° angle. The harder 
 steel alloy specimens have exhibited much 
 smaller wear scars and indicate some de- 
 gree of brittle fracture. It is possible 
 that brittleness is induced by the high 
 strain rate produced by this test. 
 
 IMPACT-SPALLING WEAR 
 
 Many types of ore crushing and grind- 
 ing equipment, such as hammer mills, rod 
 mills, and ball mills, subject wear parts 
 to repetitive impacts. The wear that re- 
 sults from fatigue, spalling, chipping, 
 
27 
 
 FIGURE 17. - High-speed impact-gouging test machine. 
 
 and fracturing can be more severe than 
 abrasive wear. This is especially true 
 of very hard alloys such as martensitic 
 steels and alloyed white cast irons with 
 their superior abrasion resistance but 
 with a propensity to spall or break after 
 large numbers of impacts (40) . Neither 
 fracture toughness nor Charpy impact 
 tests have proven useful for predicting 
 behavior of the relatively brittle, wear- 
 resistant materials subjected to repeated 
 impacts (41). 
 
 onto a test block, as described fully 
 by Blickensderf er and Forkner ( 42 ) . The 
 impacts are concentrated onto one rela- 
 tively small area on the test block. 
 Testing machines of similar concept were 
 used previously by Dixon ( 43 ) and Durman 
 (44). Machines of this type have been 
 useful for obtaining laboratory data on 
 the spalling and fracture resistance of 
 materials subjected to repeated impacts. 
 
 Ball-on-Block Equipment and Specimen 
 
 Ball-on-Block Impact-Spalling Test 
 
 A test that simulates the type of wear 
 caused by repetitive impacts is the ball- 
 on-block impact-spalling test. The test- 
 ing machine drops steel balls repeatedly 
 
 The machine consists of a steel frame, 
 a conveyor for lifting balls, ramps for 
 transporting balls , and an anvil for sup- 
 porting a specimen inside a large fun- 
 nel that collects the rebounding balls , 
 as shown in figures 18 and 19. The 
 
28 
 
 Conveyor drive motor 
 
 Conveyor 
 
 Buckets (45 cm 
 apart) 
 
 Guard screen 
 
 8.3-cm-ID by 9-cm-OD 
 steel pipe 
 
 Frame 
 
 Sand reservoir 
 
 75-mm-diam balls 
 3-m drop 
 
 Guard screen 
 
 Clamp 
 
 Specimen (opprox 
 5 by 15 by 20 cm) 
 
 Anvil 
 
 Rubber-lined hopper 
 Hopper support stand 
 
 Perforated chute 
 Floor 
 
 ///////////// 
 
 ffTfTTjy / 7 / /' //>/y/// 
 
 FIGURE 18. - Bail-on-block impact-spoiling test machine, schematic. 
 
29 
 
 FIGURE 19. - Ball-on-block impact-spa I ling test machine. 
 
30 
 
 commercial steel balls used are 75 mm in 
 diam and weigh about 1.8 kg. From the 
 top of the conveyor, the balls roll into 
 a vertical tube that directs them onto 
 the test block after a fall of 3 m. Sil- 
 ica sand is continuously fed onto the 
 test block in order to more closely simu- 
 late the condition in a ball mill wherein 
 ore is present on the liners. The number 
 of impacts is displayed by a counter that 
 is actuated when a ball interrupts a 
 light beam across the lower ramp. 
 
 Test blocks are approximately 50 mm 
 thick, 15 cm wide, and 20 cm long. The 
 15- by 20-cm face is the impact surface. 
 Blocks are surface-ground on the bottom 
 to ensure good contact with the anvil. 
 If the quality of a cast block is ques- 
 tionable, it should be X-rayed first, in 
 order that valuable test time is not 
 spent on inferior materials. 
 
 Ball-on-Block Procedure 
 
 The test block is clamped securely 
 to the anvil, and safety guards are in- 
 stalled. The balls, normally 12, are 
 placed in the machine. The sand flow and 
 conveyors are turned on. With the con- 
 veyor running at a speed of 38 m/min, 
 about 2,000 impacts per hour are deliv- 
 ered to the test block. A block is 
 tested until it breaks or 100,000 impacts 
 are delivered. During the test, the 
 weight loss and size of the developing 
 crater are measured at intervals of 
 10,000, 20,000, 35,000, 60,000, and 
 
 100,000 impacts. During operation, an 
 area within 2 m of the machine is blocked 
 off to prevent injury to personnel be- 
 cause occasionally a ball escapes from 
 the machine with sufficient energy to 
 cause severe injury. 
 
 Ball-on-Block Results and Discussion 
 
 Four types of failures have been 
 observed, namely, cold flow, flaking, 
 spalling, and breakage. The softer and 
 more ductile steel alloys tend to cold 
 flow and flake. Cold flow describes the 
 movement of bulk metal by plastic defor- 
 mation and is identified by an impact 
 crater and rounded edges of the block. 
 Flaking describes the formation and sub- 
 sequent separation from the surface of 
 thin flakes of metal that develop from 
 fatigue. Cold flow and flaking occur to- 
 gether but to differing degrees depending 
 upon the particular alloy. 
 
 Spalling and breakage tend to occur on 
 the harder (more wear-resistant) alloys. 
 Spalling describes the separation of 
 pieces of material of about 3- to 6-mm 
 dimensions. A crater develops in the im- 
 pact region as a consequence of spalling. 
 If a block fractures into two or more 
 major pieces, it is termed breakage. 
 Blocks may or may not spall before break- 
 age occurs , depending upon the composi- 
 tion and heat treatment. 
 
 Data showing typical test 
 given in table 9. 
 
 results are 
 
 TABLE 9. - Typical ball-on-block impact-spalling data 
 
 
 High-Cr-Mo 
 
 Mild steel. 
 
 Martensitic 
 
 Ni white 
 
 
 white 
 
 AISI 1020 
 
 Cr-Mo steel 
 
 cast iron 
 
 
 cast iron 
 
 
 
 
 Hardness HB. . 
 
 670 
 
 156 
 
 550 
 
 580 
 
 Number of impacts 
 
 100,000 
 
 100,000 
 
 100,000 
 
 14,000 
 
 Type of failure 
 
 Spalling 
 
 0) 
 
 Flaking 
 
 Breakage 
 
 Wt loss. . . .mg/impact. . 
 
 5.1 
 
 0.82 
 
 0.09 
 
 Neg. 
 
 Crater size: 
 
 
 
 
 
 Diameter cm. . 
 
 10.7 
 
 12.7 
 
 5.8 
 
 Neg. 
 
 Depth cm. . 
 
 1.1 
 
 0.25 
 
 0.28 
 
 Neg. 
 
 Volume cm^ . . 
 
 21.7 
 
 6.3 
 
 1.1 
 
 Neg. 
 
 Neg. Negligible. 'Cold flow, flaking. 
 
 NOTE. — 1.8-kg steel balls, 3-m drop height, 5-cm-thick test block. 
 
31 
 
 Ball-on-Ball Impact-Spalllng Test 
 
 The ball-on-ball impact-spalling test 
 is designed to create large numbers of 
 impacts on test materials in a relatively 
 short time. Designed and constructed by 
 the Bureau, the test is an advance over 
 the earlier ball-on-block drop tests be- 
 cause of at least a twenty-fold increase 
 in testing speed. The test, described 
 in greater detail by Blickensderfer and 
 Tylczak ( 45 ) , has proven especially 
 useful for studying the spalling of al- 
 loyed white cast irons and for comparing 
 the resistance to breakage of commercial 
 and experimental grinding balls. Because 
 the impacts are distributed randomly over 
 the entire surface of the ball speci- 
 men, the entire surface becomes highly 
 stressed under compression. 
 
 Ball-on-Ball Equipment and Specimens 
 
 Balls are impacted against each other 
 in a manner that provides many impacts 
 in a relatively short time. A ball is 
 dropped 3.5 m onto a column of balls con- 
 tained in a curved tube, as shown in fig- 
 ure 20. The impact from the dropped ball 
 is transmitted through the column of 
 balls with each successive ball receiving 
 a ball-on-ball impact on each side. The 
 kinetic energy of the first impact is 
 54 J. The energy of subsequent impacts 
 through the tube decreases until it is 
 about 5 J at the last impact. The energy 
 in the last ball carries it out of the 
 end of the tube onto a ramp where the 
 ball actuates a counter and rolls into a 
 bucket conveyor that carries it to the 
 top of the machine to be dropped again. 
 The machine provides random occasional 
 mixing of the balls as described in ref- 
 erence 45, to give different neighbors to 
 each ball over a period of time. 
 
 Two advantages of the design are (1) it 
 produces many Impacts quickly on a group 
 of balls, and (2) the impacts are of var- 
 iable intensity, as found in a real ball 
 mill. 
 
 The test balls are 75 mm in diam and 
 weigh about 1.8 kg. Both cast and forged 
 steel balls and cast iron balls have been 
 
 FIGURE 20. - Ball-on-ball impact-spalling 
 test machine, schematic. 
 
32 
 
 used. Because many different ball speci- 
 mens are run simultaneously, they are 
 identified by grinding small flats on 
 their surfaces. 
 
 Ball-on-Ball Procedure 
 
 To start a test, 22 balls are loaded 
 into the machine. During operation there 
 are typically 18 balls in the tube and 4 
 in the ramps and in the conveyor buckets. 
 The machine drops about 22 balls per min- 
 ute. For each ball dropped, 36 impacts 
 are created — two on each ball in the tube 
 except the one dropped and the one leav- 
 ing the tube. This gives a rate of about 
 45,000 total impacts per hour in the sys- 
 tem. The machine is run unattended. 
 When a ball breaks , the pieces block the 
 tube or ramp and all balls cease to cir- 
 culate. Although the conveyor continues 
 running, the ball drop count remains 
 fixed on the counter. An area within 2 m 
 of the machine is blocked off during op- 
 eration to prevent injury to personnel 
 because if a ball escaped from the ma- 
 chine, it could cause severe injury to a 
 person. 
 
 Balls are tested until they break or 
 until they spall excessively. Experience 
 showed that balls that have spalled over 
 150 g do not roll down the ramps; there- 
 fore, a ball is removed from the test 
 after it has lost 100 g by spalling. 
 All balls are removed from the tube and 
 weighed at intervals of 5,000 to 20,000 
 
 impacts per ball. Accurate accounting of 
 the impacts is kept on each ball. A ball 
 that fails is replaced with either anoth- 
 er test ball or a hardened steel filler 
 ball, and the test is continued. 
 
 Ball-on-Ball Results and Discussion 
 
 Four types of failures have been ob- 
 served: (1) spalling, pieces of 2 to 5 
 cm across and up to 1 cm thick, (2) mini- 
 spalling, small deep crescent pits 2 to 4 
 mm across and 2 to 3 mm deep, (3) flak- 
 ing, very thin flakes with extreme 
 surface cold work, and (4) breakage, a 
 complete failure of the ball, often by 
 fracturing through the center of the 
 ball. 
 
 The type of failure of a ball seems to 
 be dependent on hardness and the means by 
 which the balls were produced. Spalling 
 occurs mainly in cast balls and starts 
 within 50,000 impacts. Minispalling oc- 
 curs in forged, hard (about HRC 62 to 
 64) steel balls and does not start until 
 100,000 or more impacts. Flaking and 
 plastic deformation are the only damage 
 that occur to the softer (less than 
 HRC 40) forged steel balls. The flakes 
 develop after 60,000 or more impacts. 
 Breakage occurs in fully hard (greater 
 than HRC 63) steel balls and unheat- 
 treated cast balls and can occur any time 
 from a few to a few hundred thousand im- 
 pacts. Additional results are presented 
 by Blickensderfer (45-46). 
 
 SUMMARY 
 
 The research laboratories of the Bureau 
 of Mines have the capability to conduct a 
 large variety of wear tests relevant to 
 the mining and minerals processing indus- 
 tries. The tests include several perti- 
 nent ASTM standard tests and proposed 
 standard tests. The abrasive wear tests 
 include one low-stress, three-body wear 
 test (dry-sand, rubber-wheel abrasive 
 wear test); five low-stress, two-body 
 wear tests; two high-stress, three-body 
 wear tests (jaw crusher and ball mill); 
 and two high-stress, two-body wear tests 
 
 (pin-on-drum and 
 gouging) . 
 
 high-speed impact- 
 
 The repetitive impact tests include a 
 ball-on-block impact-spalling test and 
 a novel ball-on-ball impact spalling 
 test. The latter is capable of producing 
 impacts at a much faster rate than previ- 
 ous tests of this type. 
 
 Comparisons of the tests , test condi- 
 tions , and other parameters are summar- 
 ized in tables 10 and 11. 
 
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34 
 
 REFERENCES 
 
 1. American Society for Testing and 
 Materials. Evaluation of Wear Testing 
 (Sjrmp., 71st Annu. Meeting ASTM, San 
 Francisco, CA, June 23-28, 1968). ASTM, 
 Philadelphia, PA, Spec. Tech. Publ. 446, 
 1969, 132 pp. 
 
 2. Bayer, R. G. (ed.). Selection and 
 Use of Wear Tests for Metals (Symp., 
 Nov. Committee Week, ASTM, New Orleans, 
 LA, Nov. 17-21, 1975). ASTM, Philadel- 
 phia, PA, Spec. Tech. Publ. 615, 1975, 
 111 pp. 
 
 3. Borik, F. Using Tests To Define 
 the Influence of Metallurgical Variables 
 on Abrasion. Met. Eng. Q. , v. 12, No. 2, 
 1972, pp. 33-39. 
 
 4. Tweeton, D. R. Effect of Environ- 
 ment on Friction and Wear Between Quartz 
 and Steel. BuMines RI 8124, 1976, 25 pp. 
 
 5. American Society for Testing and 
 Materials. Standard Practice for Con- 
 ducting Dry Sand/Rubber Wheel Abrasion 
 Tests. G65-81 in 1981 Annual Book of 
 ASTM Standards: Part 10, Metals — Phys- 
 ical, Mechanical, Corrosion Testing. 
 Philadelphia, PA, 1981, pp. 1044-1061. 
 
 6. 
 
 Standard Method of Test for 
 
 Abrasion Resistance of Refractory Materi- 
 als at Room Temperature. C704-76a in 
 1981 Annual Book of ASTM Standards: Part 
 17, Refractories, Glass, and Other 
 Ceramic Materials; Manufactured Carbon 
 and Graphite Products. Philadelphia, PA, 
 1981, pp. 710-714. 
 
 7. Bhat, M. S., V. F. Zackay, E. R. 
 Parker, and I. Finnie. Wear Resistant 
 Alloys for Coal Handling Equipment. 
 Prog. Rep. for the period Oct. 1, 1977- 
 Sept. 30, 1979, Rep. ZP8006. Univ. CA, 
 Berkeley, CA, 1979, 63 pp. 
 
 8. Borik, F. Rubber Wheel Abrasion 
 Test. Pres. at SAE Combined National 
 Farm, Construction & Industrial Machinery 
 and Powerplant Meetings, Milwaukee, WI, 
 Sept 14-17, 1970. SAE preprint 700 687, 
 1970, pp. 1-12. 
 
 9. Levy, A. V. The Solid Particle 
 Erosion Behavior of Steel as a Function 
 of Microstructure. Wear, v. 68, No. 3, 
 1981, pp. 269-287. 
 
 10. Head, W. J., and M. E. Harr. The 
 Development of a Model To Predict the 
 Erosion by Natural Contaminants. Wear, 
 V. 15, No. 1, 1970, pp. 1-46. 
 
 11. Finnie, I., Y. Kabil, and J. Wol- 
 ok. Erosion of Metals by Solid Parti- 
 cles. J. Mater., v. 2, No. 3, 1967, 
 pp. 682-700. 
 
 12. Ruff, A. W. , and L. K. Ives. Mea- 
 surement of Solid Particle Velocity in 
 Erosive Wear. Wear, v. 35, No. 1, 1975, 
 pp. 195-199. 
 
 13. Finnie, I. Erosion of Surfaces 
 by Solid Particles. Wear, v. 3, No. 2, 
 1960, pp. 87-103. 
 
 14. Doyle, P. A., and A. V. Levy. The 
 Elevated Temperature Erosion of 1100 Al 
 by Gas Particle Flow. Paper in Proceed- 
 ings of TMS of AIME (Conf. on Corrosion/ 
 Erosion Behavior of Mater., St. Louis, 
 MO, Oct. 17-19, 1978). Metall. Soc. 
 AIME, Warrendale, PA, pp. 162-176. 
 
 15. Young, J. P., and A. W. Ruff. 
 Particle Erosion Measurements on Metals. 
 J. Eng. Mater, and Technol. , v. 99, No. 
 2, 1977, pp. 121-125. 
 
 16. Hansen, J. S., J. E. Kelley, and 
 F. W. Wood. Erosion Testing of Potential 
 Valve Materials for Coal Gasification 
 Systems. BuMines RI 8335, 1979, 26 pp. 
 
 17. Jackson, L. D. A. Controlling 
 Abrasion in Slo Slurry Pipeline Systems. 
 Can. Min. J., v. 95, No. 11, 1974, p. 42. 
 
 18. Tsai, W. , J. A. C. Humphrey, 
 I. Cornet, and A. V. Levy. Experimental 
 Measurement of Accelerated Erosion in a 
 Slurry Pot Tester. Wear, v. 68, No. 3, 
 1981, pp. 289-303. 
 
35 
 
 19. Bess, M. L. Erosion-Corrosion of 
 Cast Pump Alloys. Pres. at Pac. North- 
 west Met. and Miner. Conf., Seattle, WA, 
 May 6, 1977, 24 pp.; available from B. W. 
 Madsen, Albany Research Center, BuMines , 
 Albany, OR. 
 
 20. Postlethwaite, J., B. J. Brady, 
 M. W. Hawrylak, and E. B. Tinker. Ef- 
 fects of Corrosion on the Wear Patterns 
 in Horizontal Slurry Pipelines. Cor- 
 rosion (Houston), V. 34, No. 7, 1978, 
 pp. 245-250. 
 
 27. Bond, F. C. Lab Equipment and 
 Tests Help Predict Metal Consumption in 
 Crushing and Grinding Units. Eng. and 
 Min. J., V. 165, No. 6, 1964, pp. 169- 
 175. 
 
 28. Ellis, 0. W. Wear Tests on Fer- 
 rous Alloys. Trans. Am. Soc. Met., v. 
 30, 1942, pp. 249-286. 
 
 29. Norman, T. E., and E. M. Loeb. 
 Wear Tests on Grinding Balls. Trans. 
 AIME, V. 176, 1948, pp. 490-526. 
 
 21. Hocke, H. , and H. N. Wilkinson. 
 Testing Abrasion Resistance of Slurry 
 Pipeline Materials. Tribol. Int., v. 5, 
 Oct. 1978, pp. 289-294. 
 
 30. Robin, F. Usure des Aciers aux 
 Abrasifs (The Wear of Steels by Abra- 
 sives). Rev. Metall. (Paris), v. 8, 
 1911, pp. 47-84. 
 
 22. Elkholy, A. Prediction of Abra- 
 sion Wear for Slurry Pump Materials. 
 Wear, v. 84, No. 1, 1983, pp. 39-49. 
 
 31. Moore, M. A. A Review of Two-Body 
 Abrasive Wear. Wear, v. 27, No. 1, 1974, 
 pp. 1-17. 
 
 23. Borik, F., and D. L. Sponseller. 
 Gouging Abrasion Test for Materials Used 
 in Ore and Rock Crushing: Part I - De- 
 scription of the Test. J. Mater., v. 6, 
 No. 3, 1971, pp. 576-589. 
 
 32. Muscara, J., and M. J. Sinnott. 
 Construction and Evaluation of a Versa- 
 tile Abrasive Wear Testing Apparatus. 
 Met. Eng. Q. , v. 12, No. 2, 1972, pp. 21- 
 32. 
 
 24. Borik, F., and W. G. Scholz. 
 Gouging Abrasion Test for Materials Used 
 in Ore and Rock Crushing: Part II - Ef- 
 fect of Metallurgical Variables on Goug- 
 ing Wear. J. Mater., v. 6, No. 3, 1971, 
 pp. 590-605. 
 
 33. Mutton, P. J. High Stress Abra- 
 sion Testing of Wear Resistant Steels and 
 Cast Irons. Broken Hill Proprietary Co., 
 Melbourne Res. Lab., Clayton, Victoria, 
 Australia, Lab. Rep. MRL/PM3/78/001 , Aug. 
 1978, 49 pp. 
 
 25. Sare, I. R. , and W. B. Hall. The 
 Determination of Gouging Abrasion Resist- 
 ance by Jaw Crusher Tests. Paper in Con- 
 ference on Lubrication, Friction, and 
 Wear in Engineering, Melbourne, Austra- 
 lia, Dec. 1-5, 1980. Inst. Eng., Barton, 
 A.C.T., Australia, 1982, pp. 94-98; order 
 No. ISBN 085825-148-5. 
 
 26. Natarajan, K. A., S. C. Riemer, 
 and I. Iwasaki. Ball Wear in Magnetic 
 Taconite Grinding. Pres. at 56th Annu. 
 Meet. MN Sec. AIME and 44th Annu. Min. 
 Symp., Univ. MN, Duluth, MN, Jan. 12-13, 
 1983, 9 pp.; available from I. Iwasaki, 
 Univ. MN, Minneapolis, MN. 
 
 34. 
 
 High Stress Abrasion Test- 
 
 ing of Wear Resistant Materials. Broken 
 Hill Proprietary Co., Melbourne Res. 
 Lab., Clayton, Victoria, Australia, Tech. 
 Bull., V. 24, No. 1, 1980, pp. 38-44. 
 
 35. Mills, D. , and J. S. Mason. Eval- 
 uating the Conveying Capacity and Service 
 Life of Pipe Bends in Pneumatic Conveying 
 Systems. J. Powder & Bulk Solids Tech- 
 nol., V. 3, No. 2, 1979, pp. 13-20. 
 
 36. 
 
 Particle Size Effects in 
 
 Bend Erosion. Wear, v. 44, No. 2, 1977, 
 pp. 311-328. 
 
36 
 
 37. Mills, D. , and J. S. Mason. The 
 Effect of Particle Size on the Erosion 
 of Pipe Bends in Pneumatic Conveying 
 Systems. Paper 4 in Proceedings of the 
 Sixth (Int.) Conference on Powder Tech- 
 nology (Birmingham, United Kingdom, Mar. 
 6-9, 1979, session H) . Spec. Exhibition 
 Ltd., Croydon, Surry, England, 1979, 
 pp. H50-H96. 
 
 38. 
 
 The Influence of Velocity 
 
 on the Erosive Wear of Pipe Bends in 
 Pneumatic Conveying Systems. Paper in 
 Proceedings of the Technical Program: 
 International Powder and Bulk Solids 
 Handling and Processing (Philadelphia, 
 PA, May 15-17, 1979). Ind. and Sci. 
 Conf. Manage., Inc., Chicago, IL, 1979, 
 pp. 300-314. 
 
 39. Kostka, K. S. Coarse Particle 
 Erosion in Pneumatic Conveyor Bends. 
 Pneumotransport 4. Paper F8 in Fourth 
 Conference (International) on Pneumatic 
 Transport of Solids in Pipes (Carmel-by- 
 the-Sea, CA, June 26-28, 1978). Mater. 
 Handling Div., ASME, 1978, pp. F8-87 to 
 F8-102. 
 
 White Cast Irons Using Compact Specimens. 
 Paper in Fracture Toughness and Slow- 
 Stable Cracking (Proc. 1973 Natl. Symp. 
 on Fracture Mechanics). ASTM, Philadel- 
 phia, PA, Spec. Tech. Publ. 559, 1973, 
 pt. 1, pp. 3-14. 
 
 42. Blickensderfer, R. , and B. F. 
 Forkner. A Ball-on-Block Impact-Spalling 
 Wear Test and Results on Several Iron Al- 
 loys. BuMines RI 8794, 1983, 18 pp. 
 
 43. Dixon, R. H. T. Some Effects of 
 Heat-Treatment Upon the Impact-Fatigue 
 Life of Ni-Hard Grinding Balls. J. Iron 
 and Steel Inst., London, Jan. 1961, 
 pp. 40-48. 
 
 44. Durman, R. W. Basic Metallurgical 
 Concept and the Mechanical Testing of 
 Some Abrasion-Resistant Alloys. Foundry 
 Trade J., v. 134, May 1973, pp. 645- 
 651. 
 
 45. Blickensderfer, R. , and J. H. 
 Tylczak. A Large-Scale Impact Spalling 
 Test. Wear, v. 84, No. 3, 1983, pp. 361- 
 373. 
 
 40. Dodd, J. Progress in the Develop- 
 ment and Use of Abrasion Resistant Alloy 
 Irons and Steels in the Mining Industry. 
 Trans. -Soc. Min. Eng. AIME, v. 270, 1981, 
 pp. 1923-1930. 
 
 46. Blickensderfer, R. , J. H. Tylczak, 
 and J. Dodd. The Effect of Heat Treat- 
 ment on Spalling of a Cr-Mo White Cast 
 Iron. Paper in Wear of Materials 1983. 
 ASME, New York, 1983, pp. 471-476. 
 
 41. Diesburg, D. E. Fracture Tough- 
 ness Test Methods for Abrasion-Resistant 
 
 aU.S. CPO: 1985-505-019/5091 
 
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