Electric resistivity anomaly and martensitic phase transformation in AuCuZn alloys

The quenched Cu-16.5Al-14.9Zn alloy has been examined by electric resistivity and X-ray diffraction measurements. It is confirmed that electric resistivity anomaly (ERA), observed so far in the quenched Au-Cd and Au-Cu-Zn alloys, appears also in the present alloy quenched from the Heusler type β1-phase region followed by heating. ERA is considered to be due to annihilation of quenched-in vacancies with activation energy of about 0.33eV. The appearance of ERA modulates considerably schema of the martensitic phase transformation, especially the transformation temperature. In this paper, the reason why ERA does not appear in the case quenched from disordered β-phase region, and the quenching effect on premartensitic and other behaviours are discussed in detail.