采用超音速火焰(HVOF)喷涂技术在Q235钢基体上制备了CoCrAlYTa-10%Al2O3涂层, 利用光学显微镜(OM)、扫描电子显微镜(SEM)、能谱仪(EDS)、X射线衍射仪(XRD)、显微硬度计等研究了涂层的微观组织形貌、物相组成以及显微硬度。结果表明: 涂层组织致密且分布均匀, 孔隙率为0.44%; 涂层主要由浅灰色钴基固溶体、深灰色铬基固溶体、白色球状富钽固溶体以及黑色Al2O3组成, 其中Al2O3来自于喂料的原始组成和CoCrAlYTa合金中铝的氧化; 涂层硬度为580～630 HV0.3, 大约是Q235钢基体硬度(200 HV0.3)的3倍, 涂层具有良好的力学性能。

CoCrAlYTa-10%Al2O3 coating was deposited on Q235 steel substrate by high velocity oxygen fuel (HVOF) thermal spraying method. Microstructure, phase compositions and micro-hardness of the coating were analyzed by using optical microscope (OM), scanning electron microscope (SEM) equipped with energy dispersive spectroscope (EDS), X-ray diffractometer (XRD) and micro-hardness tester. The results show that the coating had dense and uniform microstructure with the porosity of 0.44%, and it was composed of light gray Co-based solid solution, dark gray Cr-based solid solution, white ball Ta-rich solid solution and black Al2O3 phase. The formation of Al2O3 phase was attributed to the original composition of the feedstock powders and the oxidation of element aluminum in CoCrAlYTa alloy. The micro-hardness of the coating was 580~630 HV0.3, about 3 times of that of Q235 steel substrate (200 HV0.3), indicating that the coating had good mechanical properties.