Fabrication, microstructure and micromechanical properties of Fe-based metallic glass coating manufactured by laser

Iron-based amorphous alloys have received extensive attention due to their high hardness, elastic modulus/limit and wear/corrosion resistance. In this research, an attempt has been made to develop an amorphous coating of Fe-Cr-Mo-C-B-Y metallic glass coating on the steel substrate through laser surface treatment. During the test, various process parameters are used to determine the position of the amorphous phase. After coating, the microstructure and phase distribution of the coating were analyzed by scanning electron microscope, X-ray diffraction and transmission electron microscope. Mechanical properties of the coating were analyzed by using microhardness testing, abrasion resistance and nanoindentation methods. The results show that the coating thickness varies directly with the incident laser power and interaction time. The microstructure of the coating can be divided into three layers: the first layer (columnar crystals), the second layer (the crystalline phase filled with the unit structure) and the third layer (the unit structure consists of a crystalline phase and an amorphous phase). As the heat input of laser cladding decreases, the volume fraction of the amorphous phase increases, and the average microhardness and nanohardness increase. •A new phase between the amorphous structure and the amorphous equiaxed composite structure was found.•M23C6 (M = Fe, Cr, Mo), γ-(Fe, Cr, Mo) and bcc-Fe phases were found in the coating.•Bcc-Fe phase can effectively increase the plasticity of the coating.