表面微织构协同热扩渗技术改善材料表面摩擦学性能的研究进展

Research Progress on Improvement of Tribological Properties of Materials by Surface Micro-texture and Thermal Diffusion Technology

表面微织构因其能够有效改善摩擦副之间的摩擦学性能而获得国内外学者的广泛关注。通过将表面微织构与热扩渗技术相结合,可以充分发挥2种技术的优点,进一步提高摩擦副之间的摩擦学性能,为更复杂环境下的应用提供可能。首先概述了表面微织构的常用加工方法及其所加工的织构类型,系统地归纳总结了表面织构在不同润滑工况下的减摩机理。其次,从不同的表面热扩渗技术入手,分别综述了盐浴渗氮技术、等离子渗镀技术、热氧化技术和化学气相沉积与表面织构的协同作用研究现状,根据摩擦因数、磨损量和表面硬度等性能参数,分析总结了不同复合技术的可行性以及对基体摩擦学性能的影响。相对于单一表面处理技术,复合技术能够进一步提高材料的表面硬度,延长织构的使用寿命。一般来说,复合处理表面的耐磨性显著优于单一技术处理的表面和未处理表面,但摩擦因数受工况的影响较大。最后,对该复合技术的研究发展做出总结,提出不同织构参数和热扩渗参数对基体摩擦磨损性能的影响有待进一步探究,开展极端工况下复合技术的应用基础研究,推动复合技术在摩擦领域的发展。

Surface micro-texture has attracted extensive attention from researchers because of its ability to effectively improve the tribological properties between friction pairs.At present,it has been applied in different engineering fields.However,there are some problems in the application of surface micro-texture,such as large stress concentration at texture edge,long-term wear failure,and inability to play an effective role in complex environment such as easy corrosion,low speed and heavy load.In order to improve the tribological properties of surface micro-texture,researchers begin to combine thermal diffusion technology with surface micro-texture,so as to further improve the tribological properties of friction pairs while making up for the defects of single technology and giving full play to the advantages of both technologies.Firstly,the common processing methods of surface micro-texture were summarized.Among them,laser surface micro-texture was the most widely used,which could quickly shape the surface micro-texture of complex shape.The friction-reducing mechanism of surface micro-texture under different lubrication conditions was systematically summarized and the effect of wettability on tribological properties was pointed out.Starting with different surface thermal diffusion technologies,the emphasis was put on the research status of the synergy between salt bath nitriding technology,plasma nitriding technology,thermal oxidation technology,chemical vapor deposition technology and surface micro-texture.According to the performance parameters such as friction coefficient,wear amount,surface hardness and bonding strength,the feasibility of different composite technologies and their effect on the tribological properties of the matrix were analyzed and summarized.In the composite processing,surface micro-texture can improve the depth and adhesion of the diffused layer,so the technology of surface micro-texture firstly and then thermal diffusion is usually adopted.However,relevant studies have shown that thermal diffusion before surface micro-texture can also significantly improve the tribological properties of materials,so the sequence of the combination of the two technologies needs to be further deepened.Compared with single surface treatment technology,composite technology can further improve the surface hardness of materials and prolong the service life of texture.Generally speaking,the wear resistance of composite surface is significantly better than that of single-treated surface and untreated surface,but the friction coefficient is greatly affected by working conditions.In addition,different texture parameters(shape,area ratio,size,etc.)and thermal diffusion parameters(temperature and time)directly affect the tribological properties of composite surface.There are appropriate texture parameters and thermal diffusion parameters to optimize the bonding strength,infiltration layer quality and tribological properties of the composite surface.Finally,the research and development of texture and thermal diffusion technology is summarized,and the effect of different texture parameters and thermal diffusion parameters on the tribological properties of matrix needs to be further explored,and the synergistic effect mechanism of the two is not clear.The high performance of surface treated by composite technology provides the possibility of application in more complex working conditions.It is necessary to carry out basic research on the application of composite technology in extreme working conditions to promote the development of composite technology in the field of tribology.