The anomalous strength peak and the transition of slip direction in β-CuZn

The macroscopic slip directions of β-CuZn have been determined by studying the reorientation of single crystals with three different initial orientations during tensile deformation, between room temperature and 280°C, where the anomalous strength peak takes place. The macroscopic slip directions below and above T p (the temperature at which the peak in the curve of yield stress versus temperature occurs) were quite different from each other; below T p 〈111〉 slip was predominant, while above T p non- ≥ 111 ≥ slip was predominant. This result was in good agreement with TEM observation of the dislocation structures of β-CuZn deformed below and above T p. Thus, it is concluded that the anomalous strength peak and other peculiar phenomena observed in β-CuZn at high temperatures are to be attributed to a transition of the slip direction.