THE HIGH CYCLE FATIGUE AND FRACTURE BEHAVIOR OF A SILICON CARBIDE PARTICULATE REINFORCED 2009 ALUMINUM ALLOY METAL MATRIX COMPOSITE

摘要

In this paper, the cyclic stress amplitude controlled fatigue response and fracture behavior of aluminum alloy 2009 discontinuously reinforced with silicon carbide (SiC) particulates is presented and discussed. Test specimens of the composite, in the T42 aging condition, were cyclically deformed under stress-amplitude-control at both ambient and elevated temperatures. The elevated temperature corresponded to the aging temperature of the alloy. The cyclic fatigue tests were conducted at two different stress ratios with the objective of documenting the conjoint influence of intrinsic composite microstructural effects, nature of loading, and magnitude of maximum stress on cyclic fatigue life and fracture characteristics The final fracture behavior of the composite is discussed in light of the concurrent and mutually interactive influences of composite microstructural effects, deformation characteristics of the composite constituents, nature of loading, the nature and role of microscopic cracks and resultant fatigue life.