Influence of Grain Structure and Solute Composition on the Work Hardening Behavior of Aluminum at Cryogenic Temperatures
An unrecrystallized structure is found to significantly improve the work hardening characteristics by lowering the work hardening rate during the early stages of deformation. This is in contrast to a recrystallized structure, which requires a higher work hardening rate to accommodate the greater degree of multiple slip necessary to maintain strain compatibility between the more randomly oriented grains. The stronger texture associated with the unrecrystallized structure allows deformation to occur more efficiently. The addition of magnesium also improves the work hardening characteristics by increasing the overall level of the work hardening rate. The improved characteristics of the work hardening behavior result in a parallel increase in both the strength and ductility at cryogenic temperatures. These findings are positive since they suggest a method by which improvements in the work hardening behavior and subsequent mechanical properties may be obtained through practical modifications of the microstructure and composition.
KeywordsYield Strength Fracture Toughness Flow Stress Cryogenic Temperature Plastic Stress
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