Effect of Test Variables on the Friction and Wear of Alumina

Abstract

The sliding friction and wear behavior of alumina was studied using variations in the test methods and the procedures. The counterface materials against which alumina slid were tool steel, alumina, and zirconia-toughened alumina. Wear tests were performed using the ball-on-flat, block-on-ring, pin-on-disk, washer, and reciprocating arrangements with the alumina specimen constantly in contact with the tool steel counterface. The effects of the orientation of the alumina specimen in molded block, the method of surface preparation, and the variation in counterface material on wear were also studied. It was found that the orientation did not affect wear behavior. As for the surface preparation, alumina specimens were finished by abrasion against 600-grade silicon carbide paper and grinding with alumina and diamond wheels. There was some damage to the surface observed in all of these cases, but only diamond grinding affected the wear behavior adversely. The effect of counterface on the wear behavior was very significant. The effects of the above variations on the test results are examined and interpreted with the help of scanning electron microscopy, energy dispersive X-ray analysis (EDXA), and tribological principles. The significance of the test variables is discussed in the context of anticipated ASTM standards for the testing of ceramics.