The strain amplitude-controlled cyclic fatigue, defomation and fracture behavior of 7034 aluminum alloy reinforced with silicon carbide particulates

In this paper, the cyclic stress response and stress versus strain response characteristics, cyclic strain resistance and low-cycle fatigue life, and mechanisms governing the deformation and fracture behavior of aluminum alloy 7034 discontinuously reinforced with silicon carbide particulates are presented and discussed. Specimens of the metal–matrix composite were cyclically deformed, using fully-reversed tension–compression loading under total strain amplitude control, at both ambient and elevated temperatures for the under aged and peak aged microstructural conditions. Under fully-reversed total strain amplitude control cycling, specimens of the composite exhibited combinations of cyclic hardening and cyclic softening to failure. The cyclic stress response and stress versus strain response characteristics, cyclic strain resistance, low-cycle fatigue (LCF) life, and final fracture behavior of the composite, for both the under aged and peak aged microstructures, at the two temperatures, are compared and observed differences rationalized in light of the mutually interactive influences of cyclic strain amplitude and concomitant response stress, intrinsic composite microstructural effects, deformation characteristics of the composite constituents, and macroscopic aspects of fracture.