This study deals with Al₂O₃-13wt.%TiO₂-reinforced CoCrFeMnNi high-entropy alloy (HEA) composite coatings prepared by plasma spraying. The effect of the Al₂O₃-TiO₂ ceramic phase on the microstructure, mechanical properties and high-temperature tribological performance of the as-sprayed composite coatings was investigated. The results showed that the composite coatings consisted of a HEA phase with a FCC (face-centered cubic) structure and an Al₂O₃-TiO₂ ceramic phase with a three-dimensional network structure. The coatings presented a typical layered structure with less porosity than pure HEA coatings. The three-dimensional network structure was mainly due to partially melted Al₂O₃-13wt.%TiO2 particles during the spraying process. The composite coating with Al₂O₃-TiO₂ ceramic phase had an improved plastic deformation resistance and a reduced elastic recovery resistance. Its wear rate was lower than that of the pure HEA coating. The main wear mechanisms included oxidation, wear and adhesive wear. The Al₂O₃-TiO₂ ceramic phase reduced the adhesive wear and promoted the tribological behavior of the HEA composite coating at low temperature. The excellent wear resistance of the as-sprayed coating at high temperatures was mainly due to the formation of an oxide layer on the worn surface.

本研究涉及等离子喷涂制备的Al ₂ O ₃ -13wt。％TiO ₂增强的CoCrFeMnNi高熵合金（HEA）复合涂层。研究了Al ₂ O ₃ -TiO ₂陶瓷相对喷涂复合涂层微观结构，力学性能和高温摩擦学性能的影响。结果表明，复合涂层由具有FCC（面心立方）结构的HEA相和Al ₂ O ₃ -TiO _2组成。陶瓷相具有三维网络结构。该涂层呈现出典型的层状结构，其孔隙率低于纯HEA涂层。三维网络结构主要是由于在喷涂过程中部分熔融的Al ₂ O ₃ -13wt。％TiO2颗粒。具有Al ₂ O ₃ -TiO ₂陶瓷相的复合涂层具有改善的塑性变形抗性和降低的弹性回复抗性。它的磨损率低于纯HEA涂层的磨损率。主要磨损机制包括氧化，磨损和胶粘剂磨损。Al ₂ O ₃ -TiO ₂陶瓷相减少了粘合剂的磨损并提高了HEA复合涂层在低温下的摩擦学性能。喷涂后的涂层在高温下的优异耐磨性主要是由于在磨损表面上形成了氧化层。