Strain rate sensitivity of a wrought Al-1.2% Fe alloy

Abstract

The flow stress of many commercial alloys depends on the applied strain rate. This dependence, usually called strain rate sensitivity (SRS), has been identified as a major property affecting the formability of metals and alloys. There are two common rate sensitivity parameters, measured in two different ways. The ``instantaneous`` SRS index, m{sub i}, is measured over a rapidly changing strain rate (jump test) at an essentially constant strain and presumably corresponds to a constant structure. The ``total`` SRS index, m{sub t}, is obtained by comparing two work hardening curves generated at different but constant strain rates and is associated with the formation history of the microstructure. In the present study both ``instantaneous`` and ``total`` SRS of the near eutectic AA 8079 aluminium alloy sheet are discussed in terms of strain, strain rate, grain size and the microstructure of the material.