基于热喷涂界面微纳结构设计的涂层力学性能研究进展

Progress in Research on Mechanical Properties for Coatings Based on Micro-Nano Structure Design of Thermal Spraying Interface

热喷涂陶瓷涂层在航空航天、交通运输等众多领域具有广阔的应用前景,常见的热喷涂陶瓷涂层体系包括陶瓷层、金属/合金粘结层和金属基体。由于陶瓷层与粘结层具有较大的物化性能差异,使界面成为热喷涂陶瓷涂层易发生失效的区域,极大降低了涂层的服役寿命,遏制了热喷涂陶瓷涂层更为广泛的应用。以热喷涂界面的微观和宏观结构设计为出发点,综述了微观界面和扩散对界面力学性能的影响,总结了微米-纳米颗粒的界面结构、成分连续梯度变化的涂层结构和涂层缺陷对性能的影响。同时总结了三点弯曲、显微硬度和纳米压痕对界面力学性能的系统表征方法,并结合不同测试方法的特性,给出了对应的多尺度界面力学性能的计算公式。上述结果对设计和制备高性能复合涂层具有重要的理论意义,对延长涂层服役寿命具有实际的应用价值。

Thermal spraying ceramic coatings have widely applied in the fields of aerospace,transportation,etc.Common thermal spraying ceramic coating systems include ceramic coating,metal/alloy bond-coat,and metal substrate.However,due to the great difference in physicochemical properties between ceramic coating and bond-coat materials,the interface become the vulnerable area for the failure of thermal spraying ceramic coating,thus greatly reducing the service life of the coating and restraining the wider application of thermal spraying ceramic coating.In this paper,starting from the micro and macro structure design of the thermal spraying interface,the effect of microscopic interface and diffusion on interface mechanical properties are reviewed,and that of micron-nanoparticle interface structure,continuous gradient change of composition,and coating defects on properties are summarized.At the same time,the systematic characterization methods of three-point bending,micro-hardness,and nano-indentation for the mechanical properties of the interface are summarized,and the corresponding calculation formulas for the mechanical properties of the multi-scale interface are given in combination with the characteristics of different testing methods.The above results have great theoretical significance to the design and preparation of high-performance composite coatings and have practical application value to extend the service life of coatings.