High temperature dry sliding friction and wear behavior of aluminum matrix composites (Al_3Zr+α-Al_2O_3)/Al

摘要

High temperature dry sliding friction and wear characteristics of in situ composites (α-Al_2O_3+Al_3Zr)/Al were investigated using a pin-on-disk machine. When the test temperature is at 373 K, the wear rates increase and arrive at the highest value and then decrease with the further increase of sliding velocity. However, when the test temperature is increased to 473 K, the wear rates of the composites decrease constantly with the rising of sliding velocity. The critical load transferring from stable friction to unstable friction is around 50 N at a test temperature of 473 K and a sliding velocity of 0.6 m/s. With the increase of the reinforcement volume fraction, the wear resistance of the composites increases. However, the Al_3Zr phase is detrimental to the further improvement in the wear resistance of the composites. With the increase of applied loads and test temperature, the abrasive wear, oxidation wear and adhesive wear are the main modes in the complex wear mechanisms of the composites.