THE CYCLIC STRESS-STRAIN RESPONSE OF SINGLE-CRYSTALS OF CU-16 AT -PERCENT-A1 ALLOY .1. CYCLIC HARDENING AND STRAIN LOCALIZATION

The cyclic stress-strain response of Cu-16at. %Al alloy has been explored using single crystals and conventional multistep and constant-amplitude tests. The alloy is shown to have a regular cyclic stress-strain curve with a plateau; the plateau stress is the same as that of copper but the strain range is more limited. Cyclic hardening requires large cumulative strains to reach saturation, proceeds irregularly and is associated with a remarkably constant friction stress. Strain localization is found by interferometric techniques to occur in association with the plateau and the formation of persistent slip bands.