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采用真空分段烧结法制备了两种不同粒度的高单相Cr2AlC化合物粉末,并使用超音速火焰喷涂(HVOF)方法在GH4169高温镍合金上制备了Cr2AlC涂层,对喷涂粉末及涂层进行了相结构分析,测试了涂层的显微硬度、孔隙率,并采用扫描电子显微镜(SEM)对喷涂粉末及涂层截面形貌进行了观察,结合扫描电镜能谱仪(EDS)和X射线衍射研究了涂层相组成,分析了粉末粒度对涂层微观组织结构的影响。研究结果表明:采用超音速火焰喷涂成功制备了厚度超过200μm的Cr2AlC涂层,涂层与基体紧密结合,涂层微观组织致密,采用较细的粉末有利于得到更高致密度的涂层。在喷涂过程中,有少量Cr2AlC粉末发生分解形成Cr7C3化合物。
Two kinds of single-phase Cr2AlC compound powders with different particle sizes were prepared by vacuum step sintering method. Cr2AlC coating was prepared on GH4169 high temperature nickel alloy by supersonic flame spraying (HVOF) method. The spray powder and coating Phase structure and the microhardness and porosity of the coatings were measured. The cross-sectional morphology of the sprayed powders and coatings were observed by scanning electron microscopy (SEM). Combined with scanning electron microscopy (EDS) and X-ray diffraction The phase composition of the coating was studied, and the effect of powder particle size on the microstructure of the coating was analyzed. The results show that the Cr2AlC coating with a thickness of more than 200 μm has been successfully prepared by supersonic flame spraying. The coating is tightly combined with the substrate and the microstructure of the coating is dense. The use of finer powder is more favorable for higher density coating. In the spraying process, a small amount of Cr2AlC powder decomposed to form Cr7C3 compounds.