Wear-mode mapping for the micro-scale abrasion test

The objective of this study was to develop a theoretical model and associated wear-mode map to identify the regimes in which two-body abrasion (grooving abrasion) and three-body abrasion (rolling abrasion) dominate in the micro-scale abrasive wear test (also known as the ball-cratering abrasion test). The critical condition for the transition between two-body and three-body abrasion was determined from a continuum mechanics model for the penetration of the abrasive particles into the surfaces of the ball and the specimen, coupled with considerations of equilibrium. Micro-scale abrasion tests were performed with different combinations of ball and specimen materials, under different test conditions such as abrasive concentration and load, and a wear-mode map has been produced which defines the regimes of abrasive particle motion. The map is plotted between two dimensionless groups as vertical and horizontal axes: the hardness ratio between the ball and the specimen, and a newly introduced parameter which represents the severity of contact. Experimental data generated in this work and also taken from previous studies show that the map represents behaviour in the micro-scale abrasion test well, for a wide range of ball and specimen counterface materials.