摘要
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.
采用电子探针X射线显微分析(EPMA)和X射线衍射(XRD)等表征技术研究Co-Ni-Ti-V四元系富Co-Ni区的相平衡,建立了在1000℃下3个四元体系Co-10Ni-Ti-V、Co-15Ni-Ti-V和Co-20Ni-Ti-V的等温截面。研究结果表明,随着镍含量的增加,γ(α-Co)和γ′(Co3Ti)两相区的成分范围明显扩大。基于Co-Ni-Ti-V相图,设计了具有高γ′溶解温度的合金,并对其进行了全面的性能评估,包括γ′相粗化行为和力学性能。相较于Co-Ti二元合金,所设计的Co-20Ni-10Ti-10V合金展现了较低的γ′相粗化速率以及较小的γ/γ′两相晶格错配度。值得注意的是,该合金具有优异的高温力学性能,在1000℃时的屈服强度为508 MPa。这种优异性能主要归因于合金内部存在高密度的堆垛层错剪切。
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).
