The alloying effects of Ni, W and Cr on the microstructural stability of CoNi-base alloys were investigated using a multicomponent diffusion multiple after being aged at 1000 °C for 1000 h. The diffusion multiple was carefully designed based on thermodynamic calculations. The relationships between alloy compositions and microstructural characteristics were established over a large compositional range using this single sample, and the alloying effects of Ni, W and Cr on the elemental partitioning behaviors between γ and γ′ two phases were thermodynamically analyzed using high-throughput calculation. The results together show that an increase of Ni content increases the γ′ volume faction in the long-term aged microstructures. However, the higher Ni content leads to the precipitation of the χ phase by promoting the partitioning of W from the γ′ phase to the γ phase. The decrease of W content dramatically reduces the γ′ volume faction, but the addition of Cr can properly counteract this effect by promoting the partitioning of Al and Ti from the γ phase to the γ′ phase. This study will be helpful for accelerating the development of novel γ′-strengthened multicomponent CoNi-base alloys, as well as providing experimental data to improve the thermodynamic database.

在1000°C时效1000 h后，采用多组分扩散倍数研究了Ni，W和Cr合金化对CoNi基合金显微组织稳定性的影响。基于热力学计算精心设计了扩散倍数。使用该单一样品在较大的组成范围内建立了合金成分与显微组织特征之间的关系，并使用高通量计算对Ni，W和Cr的合金化作用对γ和γ′两相之间的元素分配行为进行了热力学分析。 。结果一起表明，在长期时效的显微组织中，Ni含量的增加会增加γ'的体积分布。然而，Ni含量越高，促进W从γ'相向γ相的分配，导致χ相析出。W含量的减少极大地降低了γ′的体积分率，但是Cr的加入可以通过促进Al和Ti从γ相到γ′相的分配而适当地抵消这种作用。这项研究将有助于加速新型γ'增强多组分CoNi基合金的开发，并为改善热力学数据库提供实验数据。