高速激光熔覆铁基非晶合金涂层的组织及性能研究

Research on Microstructures and Properties of High-Speed Laser-Cladded Iron-Based Amorphous Alloy Coatings

采用Fe-Cr-B-Si非晶合金粉末,通过高速激光熔覆的方式在低碳钢表面成功制备出具有优异摩擦学性能的涂层。研究了激光功率对非晶合金涂层的显微组织、硬度以及耐磨性的影响。结果表明,涂层中非晶相的含量和分布与激光功率有关,激光功率通过改变热输入来影响稀释率和实际冷却速率。随着激光功率的增大,涂层中微观组织的生长规律发生改变,非晶相的分布位置由底部转变为顶部。当激光功率为2200 W时,涂层的微观组织主要由非晶相和未成形的晶粒组成,非晶相含量约为76%,且均匀分布于整个涂层中。非晶相的含量和分布是影响涂层硬度和耐磨性的关键因素,非晶体区比晶体区硬度提高约200 HV。当非晶相分布于涂层顶部时,会显著提高涂层的表面硬度和耐磨性。

Fe-Cr-B-Si amorphous alloy powder was successfully prepared on the surface of low-carbon steel with excellent tribological properties by high-speed laser cladding.The effects of laser power on the microstructure,hardness,and wear resistance of the amorphous alloy coating were studied.The results show that the content and distribution of the amorphous phase in the coating are related to the laser power,which affects the dilution and actual cooling rates under a change in heat input.With an increase in laser power,the growth law of microstructure in the coating changes,and the distribution position of amorphous phase switches from the bottom to the top.When the laser power is 2200 W,the microstructure of the coating is mainly composed of an amorphous phase and unformed grain nucleation.The amorphous phase content is approximately 76%and is evenly distributed throughout the coating.The content and distribution of the amorphous phase are the critical factors that affect the hardness and wear resistance of the coating,and the hardness of the amorphous region is approximately 200 HV higher than that of the crystal region.When the amorphous phase is distributed on the top of the coating,the surface hardness and wear resistance of the coating are significantly improved.