Microstructure and Mechanical Properties of Fe-Based Alloy Coatings Fabricated by Laser Cladding

The Fe-based alloy coating was prepared on the surface of 25Cr2Ni4MoV steel substrate by laser cladding. The microstructure, microhardness, shear strength, friction and wear properties of the laser cladding coating were systematically studied. The results show that a good metallurgical bond has been formed between Fe-based alloy coating and substrate. The laser cladding layer is a typical dendritic crystal, which is composed of light gray and dark gray phases. The shear strength displacement curve shows the typical characteristics of brittle fracture, with an average shear strength of 280.83 MPa. The average dry friction coefficient, wear track depth and average wear volume of laser cladding Fe-based alloy coatings are (0.45 +/- 0.01), (26 +/- 3) mu m and 0.066615 m3, respectively. The average dry friction coefficient, wear track depth and average wear volume of 25Cr2Ni4MoV substrate are (0.60 +/- 0.01), (39 +/- 3) mu m and 0.13085 m3, respectively. The laser cladded Fe-based alloy coating exhibits much better wear resistance than the steel substrate, and the shear strength of the coating displays its potential for the application in the service environment of shear stress.