TiCP/Ni60耐磨耐蚀激光熔覆层的制备及干滑动摩擦磨损性能研究

Preparation and Study on Dry Sliding Friction and Wear Properties of TiCP/Ni60 Laser Cladding Wear Resistant Coatings

本文研究了通过激光熔覆工艺在45#钢表面制备TiCP/Ni60复合材料熔覆层的组织结构及干滑动摩擦磨损性能.研究结果表明,碳素钢表层形成的1~2 mm厚度的激光熔覆层,主要由硬质相M23C6、CrB及固溶体γ-Ni等组成,大量M23C6的形成,使Ni60熔覆层硬度达到HRC 58.8,熔覆层中添加15%的TiC可使熔覆层硬度进一步提升到HRC66.3;熔覆层中TiC使其摩擦系数有所降低并趋于稳定,全载荷范围内摩擦系数的波动从0.22减少到0.062.TiC颗粒的加入可明显降低熔覆层磨损率,但TiC颗粒的存在磨损面上不形成摩擦层;熔覆层中TiC颗粒含量过多,则在干滑动磨损过程中提高耐磨性的同时,也会促使TiC破碎形成磨屑,碎裂的TiC小颗粒,加剧磨粒磨损,过多的TiC也会急剧熔覆层内部裂纹的形成和扩展,加剧剥层磨损.

In this paper, the microstructure and dry sliding friction and wear properties of TiCp/Ni60 composite coating prepared on the surface of 45# steel by laser cladding process were studied. The research results showed that the laser cladding layer with thickness of 1~2 mm formed on the surface of carbon steel was mainly composed of hard phase M23 C6、CrB and solid solution γ-Ni, etc. The hardness of Ni60 cladding layer reached HRC 58.8 due to the formation of a large amount of M23 C6. The hardness of the cladding layer can be further improved to HRC 66.3 by adding 15% TiC into the cladding layer. TiC in the cladding layer made the friction coefficient decrease and tended to be stable, and the fluctuation of friction coefficient decreased from 0.22 to 0.062 in the full load range. The addition of TiC particles can obviously reduce the wear rate of the cladding layer, but there was no friction layer on the wear surface due to the existence of TiC particles;If the content of TiC particles in the cladding layer is too much, the wear resistance will be improved in the process of dry sliding wear, at the same time, the TiC will be broken to form debris. The broken TiC particles will aggravate the abrasive wear. Too much TiC will also aggravate the formation and expansion of cracks in the cladding layer, and aggravate the delamination wear.