The interaction between Dy, Pt and Mo during the short-time oxidation of (γ’ + β) two-phase Ni–Al coating on single crystal superalloy with high Mo content
The interaction between Dy, Pt and Mo during the short-time oxidation of (γ’ + β) two-phase Ni–Al coating on single crystal superalloy with high Mo content
复制标题
高Mo单晶高温合金上(γ-β)两相NiAl涂层短时氧化过程中Dy、Pt和Mo之间的相互作用
DOI：
10.1016/j.surfcoat.2021.127999
复制
发表时间：
2021
影响因子：
5.4
通讯作者：
Liangliang Wei
中科院分区：
文献类型：
--
作者：
Bangyang Zhou;Jian He;Liang Liu;Shixing Wang;Jingyong Sun;Liangliang Wei
Mo作为镍基高温合金中典型的难熔元素，在高温氧化过程中会向外扩散到合金表面的保护层中，从而影响合金的力学性能和涂层的抗氧化性能。本文采用电子束物理气相沉积（EB-PVD）和电镀Pt的方法，在高Mo含量的单晶高温合金表面制备了含Pt和不含Pt的（γ' + β）两相Ni-34 Al-0.3Dy涂层。在1100 ℃下研究了涂层的短期氧化行为，旨在探索Dy和Pt对Mo扩散及其氧化物的有害影响的作用。结果表明，对于无Pt涂层，Mo在1 h内就已经扩散到涂层表面。在氧化初期，Dy_2O_3与MoO_3反应生成Dy_2MoO_6，抑制了MoO_3的挥发。然而，随着氧化的进行，Dy 2 MoO 6由于其差的热稳定性而分解。而对于Pt掺杂涂层，由于涂层/基体界面处的Pt层抑制了Mo的向外扩散，在整个氧化过程中没有检测到富Mo氧化物。并对可能的作用机制进行了详细的讨论。
Mo, as a typical refractory element in Ni-base superalloys, will diffuse outward to the protective coating on the alloy surface during high-temperature oxidation, which will do harm to mechanical properties of the alloy and oxidation resistance of the coating. In this paper, (γ’ + β) two-phase Ni-34Al-0.3Dy coatings with or without Pt were prepared on a single crystal superalloy with high Mo content by electron beam physical vapor deposition (EB-PVD) and Pt electroplating. The short-term oxidation behavior of the coatings was investigated at 1100 ◦C aiming to explore the role of Dy and Pt on the harmful effect of Mo diffusion and its oxides. The results show that for Pt-free coating, Mo had already diffused to the coating surface after only 1 h. The pre-existing Dy2O3 would react with MoO3 to form Dy2MoO6 thus suppressed the volatilization of MoO3 at the early stage of oxidation. However, as the oxidation proceeded, Dy2MoO6 would decompose due to its poor thermal stability. While for Ptdoped coating, no Mo-rich oxides were detected throughout the entire oxidation process due to the suppression of outward Mo diffusion by the Pt layer at coating/substrate interface. The possible mechanisms were discussed in detail.