Microstructure and Tribological Properties of FeCrBSi Amorphous Alloy Coatings by Ultra-High-Speed Laser Cladding

In this paper, the microstructure and tribological properties of ultra-high-speed laser cladded FeCrBSi amorphous alloy coatings were investigated, focusing on the effects of laser power on the evolution of the coatings' microstructure, microhardness, and tribological properties. The results showed that the FeCrBSi amorphous alloy coating was mainly composed of amorphous phase, alpha-Fe, and intermetallic compounds of Fe with B and Si. With the increase of laser power, the amorphous phase decreased and the grain size became larger. The microhardness showed a trend of decreasing and then increasing, and the microhardness reached the maximum when the laser power was 2800W, which was related to the synergistic strengthening effect of amorphous, intermetallic compounds and nanocrystals within the coating. Also, the wear resistance of the coating was found to be the best when the laser power was 2800W, and the main wear mechanism of this coating was oxidative wear with major Fe-oxides and Si-oxides. Moreover, the trace Cr2O3 generated in the oxide layer could play a certain supporting lubrication role, leading to a decrease in wear rate. [GRAPHICS] .