Research on the mechanical and tribological properties of coating reinforced by a pulsed magnetic field during the remelting process

Remelting technology can effectively reduce the pores and defects, increase the bonding strength and form good metallurgical bonding in coatings. However, coating remelting is a metallurgical process of surface recrystallisation that destroys a large number of nanocrystalline structures in the original coating during quench forming. Therefore, our research group designed a pulsed magnetic field-assisted coating remelting device and prepared coatings by applying a high pulse magnetic intensity during coating remelting. The results show that the tribological properties of the remelted coating are greatly improved by the application a pulsed magnetic field and the friction loss volume of the coating decreases from 0.285× 10⁻³ mm³ to 0.154 × 10⁻³ mm³. The distribution of residual stress is more concentrated and residual compressive stress appears. The bonding strength increases from 30 MPa to 51.6 MPa and the hardness increases from 583.0 MPa to 751.0 MPa. Furthermore, when the friction pair is in full contact with the coating, the pore reduction can significantly reduce the interference of pore defects in the coating with the friction pair. The orderly magnetic domain makes the stress distribution in the coating orderly. The residual tensile stress improves the stress mode of the coating. The grain boundaries increase after grain refinement and the crystallinity increases. All these improve the wear resistance of the coating.