Fabrication and microstructure of Fe-based amorphous composite coatings by laser cladding

Fe-based amorphous composite coatings were fabricated on AISI 1045 steel by laser cladding.The results of the X-ray diffraction and transmission electron microscopy analyses show the coating is composed of an amorphous phase in majority and a nanocrystalline phase in minority.Phase composition of the coating changes along the depth of the coating.The reasonable scanning speed for fabricating an amorphous composite coating is 3500mm/min when the laser power is 4800W and the laser beam diameter is 2mm.If the scanning speed is lower than 3500mm/min,the intensity of the two main diffraction peaks in X-ray diffraction patterns of the coatings decreases with the scanning speeds increasing.At the same time,a broad halo peak emerges and enlarges.High laser power and fast scanning speed are the essential conditions of amorphization.The coating exhibits high microhardness.