减摩耐磨激光熔覆涂层的研究现状及发展趋势

Research Status and Development Trend of Friction-Reducing and Wear-Resistant Laser Cladding Coatings

激光熔覆是一种新型的表面改性技术,对于提高材料表面的耐磨性具有重要意义。阐述采用激光熔覆技术来提高基体材料表面减摩耐磨性能方面的研究进展。首先介绍激光熔覆技术制备的Fe、Ni、Co基自熔性合金涂层及组织结构特征,指出这些涂层存在气孔、裂纹和成分偏析与组织不均匀性等缺陷。然后指出通过合理的粉末材料的选择及配比以及合理优化的熔覆工艺参数,可改善涂层性能,制备出表面性能优异的金属陶瓷复合涂层/稀土添加复合层;同时指明相比单一外部能量场,复合外部能场辅助激光熔覆制备的涂层显现出更优异的减摩耐磨效果。最后阐述新型耐磨涂层材料(自润滑耐磨涂层、高熵合金耐磨涂层,梯度耐磨涂层和纳米耐磨涂层)的组织结构和性能特征,指出高性能新型耐磨涂层可适用于多元场景,是未来研究的重点方向,并总结与展望激光熔覆制备耐磨涂层研究的发展趋势与应用方向。

Laser cladding is a new type of surface modification technology,which is of great significance for improving the wear resistance of material surfaces.The research progress in the use of laser cladding technology to improve the friction and wear behaviors of the matrix material surface was described.Firstly,the common Fe,Ni,Co-based self-fluxing alloy coatings prepared by laser cladding technology and their microstructure characteristics were introduced,and the defects such as pores,cracks,composition segregation and microstructure inhomogeneity were pointed out.Then it was pointed out that through the reasonable selection and ratio of powder materials and the reasonable optimization of cladding process parameters,the coating performance could be improved,so as to obtain the cermet composite coating/rare earth additive composite layer with excellent surface performance.And it was pointed out that compared with a single external energy field,the coating prepared by laser cladding assisted by composite external energy field shows better friction reducing and wear-resistance effect.Finally,the microstructure and performance characteristics of new wear-resistant coating materials(self-lubricating wear-resistant coating,high-entropy alloy wear-resistant coating,gradient wear-resistant coating and nano wear-resistant coating)were mainly expounded,and it was pointed out that the new high-performance wear-resistant coating can be applied to multiple scenarios,which is the focus of future research.The development trend and application direction of laser cladding preparation of wear-resistant coatings were also summarized and prospected.