Silver - Gold - Zinc

Alan Prince

Introduction

Most of the work on the Ag-Au-Zn system has concentrated on the crystallographic structure of the phases found on the section AgZn-AuZn. The binary phase AgZn exists at high temperatures as a disordered bcc structure (W-type, cI2). The high temperature phase, denoted β, transforms into a stable hexagonal structure, ζ, on slow cooling. Quenching from within the β phase region gives a metastable ordered structure, denoted β', (CsCl-type, cP2) in which Ag atoms occupy the body center lattice sites and the Zn atoms the simple cubic sites. The binary phase AuZn has the ordered β' structure as the stable phase from room temperature to its melting point. On the section AgZn-AuZn in the ternary system, addition of Au to AgZn stabilizes the CsCl-type β' phase, Fig. 1, and the ζ AgZn phase is on...