THE ROLE OF MICROSTRUCTURAL VARIABILITY ON THE ULTRA-HIGH CYCLE FATIGUE BEHAVIOR OF SICP-REINFORCED ALUMINIUM COMPOSITES

摘要

As compared to their unreinforced counterparts, discontinuously-reinforced metal matrix composites (DRC) generally have improved properties such as modulus, resistance to wear and creep, and high-cycle fatigue resistance. Metal-matrix composites such as silicon-carbide particulate-reinforced aluminum can also be processed via conventional means, making these combined attributes appealing in high-performance structures subject to cyclic loading such as in transportation and aerospace applications [1]. While the low-cycle and high-cycle fatigue behavior of SiC{sub}p-reinforced aluminum composites are well-characterized, there is currently very little data in the ultrahigh-cycle fatigue regime (N{sub}f ≥ 10{sup}7 cycles). As the materials gain favor in these increasingly demanding applications, it has become more important to understand their ultra-high cycle fatigue behavior in order to maximize their performance and safety while minimizing service costs.