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用行星式球磨技术制备了Al2O3弥散强化Ni-Cr合金粉末。为改善球磨后粉末的流动性,对粉末进行了喷雾造粒,并利用微束等离子喷涂(MPS)技术制备涂层。采用XRD、SEM等方法研究弥散强化粉末及其喷涂层的微观组织结构。试验结果表明,球磨加工后,Al2O3颗粒尺寸为微纳米级,并弥散分布于Ni-Cr基体粉末中。经微束等离子喷涂后,涂层结构较致密,孔隙率低(<2%)。涂层经650℃高温耐冲蚀试验后,发现微纳米结构涂层的耐冲蚀性良好,这与Al2O3陶瓷对涂层的增韧机理有关。
Al2O3 dispersion strengthened Ni-Cr alloy powder was prepared by planetary ball milling. To improve the fluidity of the powder after ball milling, the powder was spray granulated and the coating was prepared using micro-plasma spray (MPS) technique. The microstructure of dispersion-strengthened powder and sprayed coatings was studied by XRD, SEM and other methods. The experimental results show that after milling, the size of Al2O3 particles is in the order of micro-nano and dispersed in the Ni-Cr matrix powder. After micro-beam plasma spray coating structure is more dense, low porosity (<2%). The corrosion resistance of the micro-nano-structured coating after 650 ℃ high-temperature erosion test shows that the corrosion resistance of micro-nano-structured coating is good, which is related to the toughening mechanism of Al2O3 ceramic coating.