Investigation of friction and wear behaviors of 2024 Al and 2024 Al/SiCp composite at elevated temperatures

Abstract

Friction and wear behaviors of artificially aged 2024 Al and 2024 Al/20 vol.% SiC composite – prepared by powder metallurgy method – were investigated in the temperature range 20–250 °C. Dry sliding wear tests were conducted at a constant sliding velocity of 0.5 m/s, an applied load of 20 N, and a sliding distance of 2500 m using a pin-on-disc apparatus. Worn surfaces and wear debris were also examined by using SEM and EDS techniques. All specimens showed a transition from mild-to-severe wear above a critical temperature. In the mild wear regime, the wear rate and the friction coefficient of the composite specimen were higher than those of the unreinforced alloy. The SiC particles led to an increase in the critical transition temperature and in the severe wear regime, they caused a considerable improvement in the wear resistance. Analysis of worn surfaces and wear debris indicated that dominant wear mechanisms of the unreinforced alloy were microploughing and slight adhesion in the mild wear regime, whereas the composite specimen showed microcutting and oxidation mechanisms in the same regime. The dominant wear mechanisms shifted to severe adhesion for all specimens in the severe wear regime.