Evolution of microstructure and mechanical properties of coated Co-base superalloys during heat treatment and thermal exposure
Evolution of microstructure and mechanical properties of coated Co-base superalloys during heat treatment and thermal exposure
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DOI：
10.1016/j.msea.2015.01.060
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发表时间：
2015-03
期刊：
影响因子：
6.4
通讯作者：
R. Webler;M. Ziener;S. Neumeier;P. Terberger;R. Vaßen;M. Göken
中科院分区：
文献类型：
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作者：
R. Webler;M. Ziener;S. Neumeier;P. Terberger;R. Vaßen;M. Göken
新型γ′强化co基高温合金在高温应用方面具有令人关注的潜力。然而，对于镍基高温合金来说，为了保证足够的抗氧化性和耐腐蚀性，需要使用保护涂层。为此，本文研究了一种新型γ′强化钴基高温合金的工业涂层性能。特别讨论了长期退火后涂层工艺对基体的影响。结果表明，在时效硬化热处理过程中，喷砂工艺引起的涂层-基体界面高度变形区（表现为高度局部错取向）导致了扩散区再结晶。在扩散区发现了γ和γ′促进元素的化学梯度，导致了纳米压痕测量硬度的变化。根据成分的不同，扩散区形成了两个独立的再结晶区，一个是单相γ-(Co,Ni)，另一个是不连续生长的γ和γ′的胞状两相组织。
New γ′-strengthened Co-base superalloys show an interesting potential for high temperature applications. However, protective coatings are needed as for Ni-base superalloys to ensure sufficient oxidation and corrosion resistance. Therefore the properties of a commercial coating on a multinary new γ′-strengthened Co-base superalloy have been studied. Especially the influence of the coating process on the substrate also after long term annealing is discussed. It was found that the highly deformed areas at the coating–substrate interface indicated by a high local misorientation and caused by the sandblasting process led to a recrystallization of the interdiffusion zone during the age hardening heat treatment. A chemical gradient of γ and γ′ promoting elements was found in the interdiffusion zone causing a change in hardness as measured by nanoindentation. Depending on the composition two separate recrystallized regions formed in the interdiffusion zone, one with single phase γ-(Co,Ni) and the other with a cellular two phase microstructure of discontinuously grown γ and γ′.