Transition between mild and severe wear in aluminium alloys

Mild and severe wear behaviours of a wrought aluminium alloy (6061 Al) were studied as a function of applied load and sliding velocity. Experiments were performed under unlubricated conditions using a block-on-ring (SAE 52100 steel) configuration within a load range of 1-450 N and a sliding velocity range of 0.1-5.0 m s(-1). Three different forms of transition between mild and severe wear, namely, load-, sliding velocity- and sliding distance-induced transitions have been observed. An empirical wear transition map has been constructed to delineate the conditions under which severe wear initialed. The role of contact surface temperature on wear transitions was also studied. It was observed that the transition to severe wear occurred when the bulk surface temperature exceeded a critical temperature. The dominant wear mechanisms in each wear regime were identified and classified in a wear mechanism map. Copyright (C) 1997 Acta Metallurgica Inc.