摘要
合金中加入稀土元素可提高其抗氧化性能,目前有关Hf对CoCrAlSi涂层性能影响的报道较少。选择激光熔覆技术在GH586镍基高温合金表面上制得了不同Hf含量的CoCrAlSiHf涂层,并对涂层微观组织形态与耐高温性能进行测试分析。结果表明:激光熔覆涂层包含了大量的网状结构组织,未添加Hf涂层晶界上还形成了很多的微孔;添加Hf涂层中含有大量微孔结构,在晶界上形成了大量的微裂纹结构;涂层内主要含有γ-Co组织相,Hf含量提高可以显著减少涂层内的织构数量;添加Hf涂层内含有大量的致密氧化物,没有观察到明显的裂纹结构,添加Hf涂层经过1 100℃、96 h保温处理后形成了大量的CoCr2O4成分;未添加Hf涂层被一层厚度为10μm的氧化膜所覆盖,同时可以看到晶界区域出现了氧化的情况,Hf含量0.1%和0.3%涂层实施氧化处理后得到了含有许多微孔结构的氧化膜。
CoCrAlSiHf coatings with different Hf contents were prepared on the surface of GH586 Ni-based superalloy by laser cladding technology.The microstructure and high-temperature resistance of the coatings were tested and analyzed.Results showed that the laser cladding coating contained a large number of network structures.There were many micropores on the grain boundary of the coating without Hf addition whereas the Hf coating contained a large number of micropores and a large number of microcracks formed on the grain boundary.γ-Co was the main phase in CoCrAlSi coating,and the increase of Hf content could significantly reduce the number of textures in the coating.There was a large amount of dense oxide in the Hf coating,and no obvious crack structure was observed.After 96 h of heat preservation treatment for Hf coating,a large number of CoCr2O4 components formed.The coating without Hf addition was covered by an oxide film with a thickness of 10μm,and the oxidation was observed in the grain boundary area.The coatings with Hf contents of 0.1%and 0.3%were oxidized to form oxide films with many microporous structures.
作者
韦玉堂
崔素华
WEI Yu-tang;CUI Su-hua(School of Mechanical Engineering,Hebei University of Science and Technology,Shijiazhuang 050000,China)
出处
《材料保护》
CAS
CSCD
北大核心
2020年第3期32-32,33-35,共4页
Materials Protection
基金
河北省科技厅支撑计划课题(10213948)资助。
