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-1...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 theγ(α-Co)andγ′(Co3Ti)two-phase regions.Based on the Co-Ni-Ti-V phase diagram,alloys with highγ′solvus temperature were designed,and their comprehensive properties,includingγ′coarsening behavior and mechanical properties,were thoroughly investigated.Compared to Co-Ti-based superalloys,the Co-20Ni-10Ti-10V alloy exhibits lower coarsening rates ofγ′precipitates andγ/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.展开更多
基金supported by the National Natural Science Foundation of China(Nos.51831007,52371007)the Shenzhen Science and Technology Program,China(No.SGDX20210823104002016)the Guangdong Basic and Applied Basic Research Foundation,China(No.2021B1515120071).
文摘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 theγ(α-Co)andγ′(Co3Ti)two-phase regions.Based on the Co-Ni-Ti-V phase diagram,alloys with highγ′solvus temperature were designed,and their comprehensive properties,includingγ′coarsening behavior and mechanical properties,were thoroughly investigated.Compared to Co-Ti-based superalloys,the Co-20Ni-10Ti-10V alloy exhibits lower coarsening rates ofγ′precipitates andγ/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.
