Effect of temperature on friction and wear characteristics of as-cast SiC_p/A356 composite

The influence of temperature change on the dry sliding friction and wear characteristics of as-cast SiCp /A356 composite was investigated on UMT-2 tribometer by using Al2 O3 ceramic ball as dual material. The high temperature friction and wear behavior of the composite material were analyzed by SEM, EDS and Olympus confocal laser scanning microscope. The results show that the wear rate of the composites is very sensitive to the change of temperature. When temperature is less than 200 ℃, the wear rate and its change are relatively smaller. The wear mechanism is mainly oxidation wear, which is one form of mild wear. When the temperature reaches or is above 250 ℃, the wear rate increases quickly. And on the wear surface, there are severe plastic flowing wear traces, the bulge of stacked swarf adhesion and a large number of large sized wear debris. The wear mechanism mainly is adhesive wear and there is a small amount of oxidation wear as well. At oxidation wear stage, although the friction coefficient changes, but it is relatively stable. While at adhesion wear stage, the friction coefficient becomes extremely unstable, and a sharp peak appears.