The effect of crystallographic grain orientation of polycrystalline Ti on ploughing under scratch testing

Abstract Plastic ploughing of polycrystalline Ti samples subjected to scratching was studied experimentally and using molecular dynamic simulation. Crystallographic orientation of Ti grains is found to substantially affect the formation of pile-ups at scratch flanks and the residual depth of scratch grooves. This effect is concerned with the difference in plasticity of the grains with different orientations in the zone of a tribological contact. It is shown that the most preferred grain orientations in terms of enhancement of their resistance to abrasive wear are those that can favor strain hardening of the material in the scratch groove. The applicability of the H / E and H 3 / E 2 ratios for the prediction of resistance of grains with different orientations to abrasive wear is investigated. It is found that the H / E ratio provides better agreement with the residual depth of scratch grooves than the hardness or H 3 / E 2 ratio.