超高速激光熔覆FeAl-TiB_(2)复合涂层的摩擦磨损性能研究

Friction and Wear Properties of FeAl-TiB_(2) Composite Coating Produced by Extreme High-Speed Laser Cladding

为了提高FeAl基复合涂层在高温(600℃)下的摩擦磨损性能,以Fe粉末、Al粉末和TiB_(2)粉末为原始粉末,采用超高速激光熔覆工艺在32Cr3Mo1V钢表面原位制备了不同TiB_(2)质量分数的FeAl-TiB_(2)复合涂层。研究了复合涂层的相组成、组织和磨损机理。结果表明:原位合成的复合涂层与基体之间形成了良好的冶金结合,随着TiB_(2)质量分数的增加涂层表面更加致密,重熔的TiB_(2)以网格状的形式分布在复合涂层表面。TiB_(2)增强相能够承受摩擦过程中的压应力与剪切力,有效提升了复合涂层的耐磨性能。当TiB_(2)质量分数为10%时复合涂层的摩擦系数和磨损率最低,耐磨性能最佳。随着TiB_(2)质量分数的上升,磨损方式已由塑性变形逐步向磨粒磨损转变,同时伴随着氧化磨损。

To improve the friction and wear performance of FeAl-based composite coatings at high temperatures(600 ℃),different FeAl-TiB_(2) composite coatings with varying TiB_(2) mass fractions were in situ prepared on the surface of 32Cr3Mo1V steel using an ultra-fast laser cladding process,with Fe powder,Al powder,and TiB_(2) powder as the raw materials.The phase composition,microstructure and wear mechanism of the composite coating were studied.The results showed that the in-situ composite coating formed a good metallurgical bond with the substrate.With the increase of the mass fraction of TiB_2,the coating surface became denser,and the remelted TiB_(2) was distributed on the surface of the composite coating in the form of grid.The TiB_(2) reinforced phase can withstand the compressive stress and shear force during the friction process,which effectively improves the wear resistance of the composite coating.When the mass fraction of TiB_(2) is 10%,the friction coefficient and wear rate of the composite coating are the lowest,and the wear resistance is the best.With the increase of the mass fraction of TiB_2,the wear mode gradually changes from plastic deformation to abrasive wear,accompanied by oxidation wear.