以Ni60-10% hBN(质量分数/%)复合粉末为原料,采用激光熔覆技术在TC4合金表面成功制备出了γ-Ni/TiC/TiB2＋CrB-Ni3B/hBN高温自润滑耐磨复合涂层。在600 ℃下分别将该复合涂层保温10、30、50 h,研究不同时长的高温时效处理后该复合涂层的物相、组织形貌、显微硬度和摩擦学性能的变化及其机理。结果表明,高温时效处理前后复合涂层的物相组成基本不变,高温时效处理50 h后的涂层平均显微硬度由时效处理前的1162 HV0.2降为910 HV0.2 ;涂层的摩擦系数及磨损率由时效处理前的0.225和4.85×10-6 mm3/Nm分别升高到0.375和5.35×10-6 mm3/Nm,但相较于基体仍然具有良好的耐磨减摩性能,在600 ℃下长时间时效处理后,该复合涂层的物相、组织和摩擦学性能都表现出良好的高温稳定性。

The γ-Ni/TiC/TiB2+CrB+Ni3B/hBN high-temperature self-lubrication anti-wear composite coatings were fabricated on TC4 titanium alloy by laser cladding, using the Ni60-10%hBN preplaced composite powders. The phase composition, microstructure, microhardness, tribological property of the composite coatings were evaluated after heating at 600 ℃ for 10, 30, 50 h. The results show that the phase composition in the coatings changes a little. The microhardness of the composite coating dips to 910 HV0.2 form 1 162 HV0.2 after aging at 600 ℃ for 50 h. The friction coefficient and wear rate of the composite coating rise to 0.375 and 5.35×10-6 mm3/Nm form 0.225 and 4.85×10-6 mm3/Nm, but they still have good self-lubrication anti-wear performance compared with the TC4 alloy substrate. The phase composition, microstructure and tribological properties of the composite coatings present good high-temperature stability after 50 h aging treatment.