Microstructure and wear resistance of Fe-based coatings formed by plasma jet surface metallurgy

The Fe-based alloys were deposited on AISI1020 steel using homemade DC-plasma jet surface metallurgy equipment, and metallurgical bonding was obtained between coating and substrate. An optical microscope (OM), scanning electron microscope (SEM), microanalysis and X-ray diffraction analysis (XRD) were employed to observe the microstructure and analyze the chemical compositions of coatings. The hardness and wear resistance of the coatings were tested. The results show that the prime phase (γ-(Fe,Ni)) and other phase, such as (Cr,Fe)7(C,B)3 exist in the coatings. Because of the solution hardening, refined crystal hardening and second phase particle strengthening, wear resistance of Fe-based coating was enhanced. In addition, the wear mechanism is discussed based on microscopic observation of the worn surface.