中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 21 No. 10 October 2011 |
（Key Laboratory for Anisotropy and Texture of Materials, Ministry of Education,
Northeastern University, Shenyang 110819, China）
Abstract:The Co−Cr−W ternary system was critically assessed using the CALPHAD technique. The solution phases including the liquid, g-Co, e-Co and a-Cr were described by a substitutional solution model. The σ, μ and R phases were described by three-sublattice models of (Co,W)8(Cr,W)4(Co,Cr,W)18, (Co,Cr,W)7W2(Co,Cr,W)4 and (Co,W)27(Cr,W)14(Co,Cr,W)12, respectively, in order to reproduce their homogeneity ranges. A self-consistent set of thermodynamic parameters for each phase was derived. The calculated isothermal sections at 1 000, 1 200 and 1 350 °C are in good agreement with the experimental data. A eutectoid reaction of R m+g-Co+s in this ternary system was predicted to occur at 1 022 °C.
Key words: Co−Cr−W system; Co-based superalloys; phase diagram; thermodynamics; σ phase; μ phase; R phase
