The orientation dependence of the yield stress of Cu3Au

Tensile yield stress measurements over the temperature range 77 to 650 K have been made on single crystals of ordered Cu3Au for four different orientations. The yield stress increased with increasing temperature above 200 K, showing a small orientation dependence. The yield stress temperature dependence showed fairly good agreement with that predicted by Pope's theory which was based on the disordering process. The anomalous temperature dependence of the yield stress could not be explained by a simple thermal activation process, such as thermally activated (010) cross slip.