Partial phase diagram of the Au–Ag–Zr ternary system

Abstract

On the basis of Au–Ag, Au–Zr and Ag–Zr binary phase diagrams, the 700 °C isothermal section of the gold–silver-rich field in the Au–Ag–Zr ternary system was established by X-ray diffraction analysis, electron probe microanalyses (EPMA) and optical microscopy. It is found that there is the long single-phase region, Au(Ag) or Ag(Au), along the Au–Ag binary isomorphous system on the gold–silver-rich side of the 700 °C isothermal section. The solid solubility of Zr in Au(Ag) decreases with the silver content of Au(Ag). It is confirmed that the partial 700 °C isothermal section consist of five single-phase regions: solid solution Au(Ag) or Ag(Au), Au 4Zr, Au 3Zr, Au 2Zr and AgZr; seven two-phase regions: Au 4Zr + Au(Ag), Au 3Zr + Au(Ag), Au 2Zr + Au(Ag), Au 4Zr + Au 3Zr, Au 3Zr + Au 2Zr, AgZr + Au(Ag) and AgZr + Au 2Zr; three three-phase regions: Au 4Zr + Au 3Zr + Au(Ag), Au 3Zr + Au 2Zr + Au(Ag) and Au 2Zr + AgZr + Au(Ag). No new ternary compound is formed in the gold–silver-rich field of the Au–Ag–Zr ternary system.