Cyclic plastic strain response and fatigue fracture of 7034 aluminum alloy reinforced with silicon carbide particulates: Influence of aging condition

In this research paper the cyclic stress response, cyclic stress-strain response, cyclic strain resistance characteristics, fatigue life and fracture behavior of aluminum alloy 7034 discontinuously-reinforced with silicon carbide particulates is presented and discussed. Specimens of the metal matrix composite were cyclically deformed under total strain amplitude control at both ambient and elevated temperatures for both the underaged and peak aged microstructural conditions. Under total strain-amplitude control, specimens of the composite exhibited combinations of hardening and softening to failure. The cyclic stress response and stress-strain response characteristics, cyclic strain resistance, fatigue life and fracture behavior of the composite for both the underaged and peak aged microstructures, at the two temperatures, are compared and observed differences rationalized in light of the competing and mutually interactive influences of cyclic strain amplitude and resultant response stress, cyclic stress amplitude, intrinsic composite microstructural effects, deformation characteristics of the composite constituents and macroscopic aspects of fracture.