LOW-TEMPERATURE SERRATED FLOW IN CU-2BE A LLOY

In the homogenised Cu-2Be alloy discontinuous how has been investigate d at 4.2 K. The behaviour of serrated yielding is dependent on the str ain rate. The strain rate sensitivity of the yield stress is slightly negative, whereas the stress for the onset of serrated flow increases with increasing strain rate. The character of serrated flow changes wi th the strain rate. The frequency of stress drops depends on the strai n; at the beginning of deformation it depends on the strain rate, wher eas at higher stages of deformation achieves its saturated value. Thes e findings are discussed on the basis of current concepts of the natur e of low temperature instability.