Tribological properties of Ti-aluminide reinforced Al-based in situ metal matrix composite

For structural application of moving components, the tribological properties (friction and wear) are considered to be one of the major factors controlling the performance. In recent years, lightweight metal matrix composites (MMC) have received wider attention for their technological application, such as automotive parts etc. This paper reports the tribological behavior of Al based composites reinforced with in situ TixAly and Al2O3 particles. The wear experiments were performed on a newly designed fretting tribometer to evaluate the role of intermetallic particulates on the wear performance of in situ composites against bearing steel under the ambient conditions of temperature (22-25 degrees C) and humidity (50-55% RH). Based on the topographical observation of the worn surfaces the plausible wear mechanisms are discussed. An important result is that Al-based composites with 20 vol% reinforcement exhibit an extremely low coefficient of friction of 0.2 under untubricated conditions. Also, around five times lower wear volume is measured with 20 vol% composites when compared to unreinforced Al. (c) 2005 Elsevier Ltd. All rights reserved.