稀土对Fe基合金激光熔覆层抗磨性能的影响

Effect of La_2O_3 on Wear Resistance of Laser-Cladded Fe-Based Alloy Coatings

在Fe基合金粉末中引入La2O3,通过激光熔覆得到了同基材结合良好的熔覆层,用扫描电子显微镜观察了稀土含量对熔覆层组织形貌的影响,用显微硬度计测量了熔覆层的硬度分布,并采用MM-200型摩擦磨损试验机考察了不同熔覆层在干摩擦条件下的摩擦磨损性能.结果表明,引入稀土有利于促进晶粒细化,提高熔覆层的组织均匀性及表面硬度,从而改善熔覆层的摩擦磨损性能.

Laser-cladded Fe-based alloy coatings of different La2O3 contents were prepared on 16Mn steel surface using a CO2 laser device. The effect of La2O3 content on the microhardness, microstructure, and tribological behaviors of the resulting laser-cladded coatings was investigated. Thus the microhardness of the laser-cladded coatings was measured, the microstructure and worn surfaces morphologies of the coatings were examined on a scanning electron microscope, and the friction and wear behaviors of the coatings sliding against AISI-1045 steel in a ring-on-block configuration were evaluated by MM-200 friction and wear tester. It was found that the incorporation of the rare earth oxide contributes to increase the hardness and refine the microstructure of the coatings, which leads to increase wear-resistance of the coatings. The inclusion of the rare earth oxide causes changes in the wear mechanisms of the laser-cladded coatings, which corresponds to the differences in the wear-resistance of the coatings. It was suggested to control the rare earth content as 1.2% so as to acquire the optimized comprehensive tribological properties of the laser-cladded Fe-based alloy coatings.