Elastic Behavior and Phase Stability of the β₁-AgZn Alloy

抄録

To elucidate the dynamical mechanism of the β₁ to ζ transition the elastic constants of metastable β₁ phase of Ag–Zn alloys containing 46.5 and 48.5 at.% Zn are measured in the range between room temperature and the β₁ to ζ transition temperature using an ultrasonic pulse-echo overlapping method.
The elastic constants C_L[110]=(C₁₁+C₁₂+2C₄₄)⁄2 and C₄₄ decrease linearly with increasing temperature up to 340 K and then fall more rapidly on further heating. On the other hand, C₁₁ decreases linearly on heating up to 340 K and then increases at higher temperatures. Furthermore, C_L[111]=(C₁₁+2C₁₂+4C₄₄)⁄3 which is mainly related to the β₁ to ζ transition mechanism decreases rapidly above 340 K. These elastic constants show a characteristic temperature hysteresis with heating and cooling. Based on the obtained results, we discuss the transition mechanism and stability of the β₁ phase.