Abstract
The tensile tests of copper-zinc and copper-aluminium alpha solid solution polycrystalline specimens were investigated over the temperature range from room temperature up to 850°C. In the highly concentrated alloys of 70:30 brass and Cu-7 wt% Al alloy, peculiar yield phenomena were observed at temperatures above about 500°C, and also the change in yield stress with temperature discontinuously showed a peak at about 500°C. On the basis of the results obtained, the mechanisms of micro-creep phenomena proposed by Cottrell-Jaswon and Suzuki were compared, and it was found that the former was considered to preferentially contribute to these phenomena. The abnormal behaviours of yielding could be explained by the dragging motion of dislocations and the Johnston’s mechanism for yielding. These theoretical predictions were also confirmed experimentally.
