The effect of strain rate on the anomalous peak of yield stress in β-CuZn alloy

The effects of strain-rate and temperature on the anomalous peak in the large grained β-CuZn alloy have been investigated. It has been found by tensile tests that as the strain rate increases the anomalous peak moves to a higher stress and temperature region. The flow curves obtained by the load relaxation tests represent that two types of deformation modes are involved in the deformation competing with each other at particular temperature and strain-rate. The anomalous yield behavior is closely associated with the Type I mode revealing slight positive strain rate dependence, whereas the Type II mode represents the normal yield behavior showing negative temperature dependence and positive strain rate dependence. It is considered that the flow curves follow the mode of lower stress at a specific temperature and strain-rate, which accords well with the experimental results. The positive strain-rate dependence of yield stress indicates that the yield stress anomaly in the β-CuZn alloy can be described better by the local climb-locking model.