Laser Surface Alloying of Low Carbon Steel Using High-entropy Alloy Precursors

The Al0.5 CoCrCuFeNi high-entropy alloy powders with simple face-centered-cubic (FCC) solid solution structure were introduced into the surface layer of a low carbon steel during laser surface alloying. A high performance surface layer with extremely fine martensite as the dominant phase was obtained, resulting in a great improvement in microhardness, wear resistance, and corrosion resistance. The great enhancement of microhardness and wear resistance of the laser alloyed layer is mainly due to the formation of extremely fine martensite hard phase, the solid solution strengthening of the alloying elements in supersaturated α-Fe solid solution, and the existence of size effect and strain effect under rapid solidification. The enhancement of corrosion resistance is due to the alloying of Al, Co, Ni, Cr and Cu in the laser alloyed layer.