Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 15 No. 4 August 2005|
（Kunming Institute of Precious Metals, Kunming 650221, China）
Abstract: On the basis of Au-Ag, Au-Dy and Ag-Dy binary phase diagrams, the 700℃ isothermal section of Au-Ag-Dy ternary system(Dy≤35%, mole fraction) was established by X-ray diffraction analysis, differential thermal analysis and optical microscopy. It is found that there is a 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℃ isothermal section and between the binary compound Au2Dy and Ag2Dy there is the all proportional solid solution, (Au2Dy) or (Ag2Dy). It is confirmed that the partial 700℃ isothermal section consists of six single-phase regions: solid solution Au(Ag) or Ag(Au), (Au2Dy) or (Ag2Dy), Au6Dy, Au51Dy14, Au3Dy and Ag51Dy14; nine binary-phase regions: (Au2Dy)+Au(Ag), Au6Dy+Au(Ag), Au(Ag)+Ag51Dy14, Ag51Dy14+(Au2Dy), Au3Dy+(Au2Dy), Au3Dy+Au51Dy14, Au51Dy14+Au6Dy, Au51Dy14+Au(Ag) and Au(Ag)+Au3Dy; four ternary regions: Ag51Dy14+(Au2Dy)+Au(Ag), (Au2Dy)+Au(Ag)+Au3Dy, Au(Ag)+Au3Dy+Au51Dy14 and Au51Dy14+Au(Ag)+Au6Dy. No new ternary compound is formed in the gold-silver-rich field(Dy≤35%) of the Au-Ag-Dy ternary system.
Key words: Au-Ag-Dy ternary system; phase diagram; isothermal section