中国有色金属学报(英文版)
Transactions of Nonferrous Metals Society of China
| Vol. 35 No. 11 November 2025 |
（1. Fujian Provincial Key Laboratory of Materials Genome Engineering, College of Materials, Xiamen University, Xiamen 361005, China;
2. Xiamen Key Laboratory of High Performance Metals and Materials, Xiamen University, Xiamen 361005, China;
3. Institute of Materials Genome and Big Data, Harbin Institute of Technology, Shenzhen 518055, China）
Abstract:The Co-Ni-Ti-V quaternary phase diagrams within the Co-Ni-rich region were investigated using the electron probe X-ray micro-analyzer (EPMA) and X-ray diffraction (XRD). Three isothermal sections corresponding to the Co-10Ni-Ti-V, Co-15Ni-Ti-V, and Co-20Ni-Ti-V quaternary systems at 1000 °C were experimentally established. The results indicate that increasing Ni content markedly broadens the γ (α-Co) and γ′ (Co3Ti) two-phase regions. Based on the Co-Ni-Ti-V phase diagram, alloys with high γ′ solvus temperature were designed, and their comprehensive properties, including γ′ coarsening behavior and mechanical properties, were thoroughly investigated. Compared to Co-Ti-based superalloys, the Co-20Ni-10Ti-10V alloy exhibits lower coarsening rates of γ′ precipitates and γ/γ′ lattice mismatch. Notably, it possesses exceptional high-temperature mechanical properties, with a yield strength of 508 MPa at 1000 °C. This superior performance is primarily attributed to the presence of a high density of stacking fault shear.
Key words: Co-Ni-Ti-V; phase equilibria; partition coefficient; coarsening rate; mechanical property
