THE VARIATION OF HARDNESS AND WEAR COEFFICIENT IN SLIDING WEAR OF COPPER AND ALUMINUM-ALLOYS

This work presents an experimental investigation of the effect of normal loads, traveling distances and sliding velocities on the wear resistance, wear coefficient and Vickers microhardness (HV) of copper and aluminum base alloys. For this purpose, a versatile test rig capable of testing surfaces with different geometrical contacts is designed and constructed. Results are presented for two different wear techniques: pin-on-cylinder with side-on and end-on arrangements. Particular attention is focused on the possible effect of normal load and sliding distance upon hardness of the worn surface during wear tests. Measurements of microhardness for the worn surfaces show that there is a substantial increase in the hardness as the normal load and traveling distance increase. The wear coefficient is calculated for the worn surface of each test and plotted against the tested conditions, considering the variation of hardness. The wear coefficient is found to be of an order of magnitude of 10(-6) for both materials tested.