The effects of solutes on precipitated phase/matrix interface stability and their distribution tendencies between the two phases in Co-based superalloys
The effects of solutes on precipitated phase/matrix interface stability and their distribution tendencies between the two phases in Co-based superalloys
复制标题
DOI：
10.1016/j.commatsci.2022.111547
复制
发表时间：
2022-08-01
影响因子：
3.3
通讯作者：
Wang, Qi
中科院分区：
文献类型：
--
作者：
Jin, Huixin;Zhang, Jianxin;Wang, Qi
D 019-Co 3X和μ-Co 7 X6是钴基高温合金中两种常见的有害相。在这项工作中，D 019-Co 3X/γ和μ-Co 7 X6/γ界面的密度泛函理论（DFT）计算进行了研究。在此基础上，分析了不同溶质对界面稳定性的影响。对于D_（019）/γ界面，Ti的加入降低了界面的稳定性，降低了D_（019）形核的驱动力。W、Re和Ru可以增加界面稳定性，促进D 019的成核。对于μ/γ这些溶质都增加了界面的分离功，但与其它溶质相比，Ti几乎不能增加界面的分离功，也不能促进μ相的形核。此外，还讨论了D 019（或μ）和γ之间的溶质分配行为。发现当Ti等溶质分布在D 019中时，其能量都比γ内稳定，并且都有从γ向D 019扩散的趋势。对于μ和γ相，Ti不同于其他溶质，因为它的能量分布在γ中比分布在μ中更稳定。在μ的生长过程中，γ内的Ti没有向μ扩散的趋势.从界面稳定性和原子扩散的角度揭示了溶质对D 019和μ相析出的影响。
D019-Co3X and & mu;-Co7X6 are two common detrimental phases in Co-based superalloys. In this work, the D019-Co3X/& gamma; and & mu;-Co7X6/& gamma; interfaces were studied by density functional theory (DFT) calculation. On this basis, the influence of different solutes on the interfacial stability has been analyzed. For the D019/& gamma; interface, Ti can lower its stability and reduce the driving force of D019's nucleation, which is different from other elements. W, Re, and Ru can increase the interfacial stability, promoting the nucleation of D019. For & mu;/& gamma;, these solutes all increase the work of separation of the interface, but compared with other solutes, Ti can hardly improve the work of sepa-ration and facilitate the nucleation of the & mu; phase. In addition, the solute distribution behaviors between D019 (or & mu;) and & gamma; have been discussed. It is found that when solutes such as Ti are distributed in D019, the energies are all more stable than they are inside & gamma;, and they all have the tendency to diffuse from & gamma; to D019. For the & mu; and & gamma; phases, Ti is different from other solutes since its energy to distribute in & gamma; is more stable than that distributed in & mu;. During the growth of & mu;, the Ti inside & gamma; has no tendency to diffuse toward & mu;. These results reveal the solutes' effects on the precipitation of the D019 and & mu; phases at the atomic scale from the perspective of interfacial stability and atomic diffusion.