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In this work, Fe-based alloy coatings were prepared on the surface of ductile iron by laser cladding. To improve its wear resistance and consider the economic and time cost of other post-treatment processes, laser remelting was chosen to strengthen the coatings. The effect of laser remelting energy density (0−11.45 J/mm2) on the phase composition, microstructure evolution, hardness, and wear resistance of the coatings were investigated. The results show that the coating consists of γ-(Fe, Cr) and carbides and that remelting energy density has little effect on its phase composition. After remelting, the hardness uniformity of the coating was significantly improved, but increasing the remelting energy density had little effect on it. The hardness and wear resistance of the coatings were inversely related to remelting energy density. At a low remelting energy density of 5.66 J/mm2, the hardness and wear mass loss of the coating were 111.49% and 54.36% of the original coating, respectively. The mechanism for the improved hardness and wear resistance is the microstructure refinement induced by laser remelting. Increased remelting energy density reduces the microstructure refinement of the coating, but the coatings still showed good hardness and wear resistance due to the diffuse distribution of carbides at higher remelting energy density conditions of 9.43-11.45 J/mm2. [ABSTRACT FROM AUTHOR]

In the present study, the Stellite 12 coating was prepared on 304 stainless steel using laser cladding technology. The phase composition, microstructure, and friction behavior of the cladding layer under the four loads were analyzed. The results showed severe lattice distortion in the coating. As the temperature gradient and solidification rate were diverse in each region, the upper, middle, and lower sections of the coating layer exhibited various microstructure morphologies. The intergranular part of the cladding layer was mainly the eutectic structure, and the inner crystal was mainly Co solid solution. Spalling and adhesive phenomena appeared at the bottom of the specimen when the action was under a load of 90 N and 150 N. The average wear of the cladding layer improved with the increase in load, the shear stress and temperature in the contact zone were enhanced distinctly, and the specimen became more prone to plastic deformation and wear intensification. [ABSTRACT FROM AUTHOR]

In this study, a laser-cladding-fabricated Fe-based alloy coating was processed using power spinning technology. The influences of power spinning treatment on the coating have been discussed. The results show that after the power spinning treatment, the surface roughness of the coating was reduced to Ra = 2.4 μm, and the average grain size of the surface layer was refined from the original 46.32–35.25 nm. The surface structure of the cladding layer was crushed and elongated. The average hardness of the coating surface following power spinning treatment (544.5 HV) was much greater than the average hardness of the original coating surface (438.7 HV). After power spinning, the degree of work hardening of the sample increased and the strength increased, while the plasticity and elongation decreased. Meanwhile, brittle fractures in the upper part of the coating were more evident after the power spinning treatment. [ABSTRACT FROM AUTHOR]