热喷涂Ni基复合涂层重熔处理的研究现状

热喷涂Ni基复合涂层因具有耐磨、耐腐蚀及耐高温等特点,被广泛应用于机械零件的表面修复和保护。但是,热喷涂层为典型的层状结构,具有微缺陷含量较高、与基体结合强度低等特点,难以适应苛刻的工作环境,其应用和发展受限。重熔处理可以消除热喷涂层的层状结构,消除或部分消除孔隙、裂纹等微缺陷,使涂层与基体形成冶金结合,提高涂层的使用性能。本文首先介绍了几种适用Ni基复合涂层的重熔技术(即激光重熔、火焰重熔、感应重熔等),随后介绍了重熔处理对Ni基复合涂层表面完整性(即微缺陷、结合强度和硬度)的影响,接着分析了重熔处理对Ni基复合涂层两种服役性能(即耐磨性、耐腐蚀性能)的影响,最后总结了目前在关于Ni基复合涂层重熔技术研究中存在的问题,进而探讨了相应的解决方案,并指出挖掘新的表面重熔技术和对不同的材料体系进行针对性研究是未来重点发展的方向。

Research Status on remelting of Thermal Sprayed Ni-based composite coatings

Owing to the high abrasion resistance, anti-corrosion, temperature resistance and many other features, thermal sprayed Ni-based composite coatings are widely used in the surface repairing and protection. But the thermal sprayed coatings have lamellar structure and a lot of micro-defects, the bonding strength between the coating and substrate is poor. These problems limit its application and development. The remelting technology could solve the problem by eliminating the lamellar structure and the micro-defects. The remelted coating is metallurgically bonded to the substrate. The remelting technologies which are suitable for Ni-based composite coatings were summarized, such as the laser remelting, flame remelting and induction remelting, etc. The influence of remelting treatment on surface integrity, micro-defects, bonding strength and hardness of Ni-based composite coatings was introduced. The influcene of remelting on wear and corrosion resistance of Ni-based composite coatings was analysed. Finally, the problems and advice about the remelting technology of Ni-based composite coatings were put forward in current study. Some key aspects of the Ni-based composite coatings were pointed out.