Forming mechanism and tribological properties of a Ni-based coating prepared from transverse static magnetic field-assisted supersonic plasma spraying

Abstract

Magnetic field-assisted forming represents an environmentally friendly, contactless and high-efficiency technology for the development of advanced in situ manufacturing. The application of this technology provides a new concept for improving the properties of ferromagnetic wear-resistant coatings. In this study, we combine magnetic field-assisted forming with supersonic plasma spraying to prepare a Ni-based coating assisted by a transverse static magnetic field. The porosity of the magnetic field-assisted coating is below 2%, the hardness of the coating increases from 638.46 to 785.45 MPa and the tribological coefficient decreases from 0.466 to 0.422. The presence of the static magnetic field directly affects the bubble movement during the forming process of the coating, which makes the bubbles escape outward and reduces the porosity of the coating. The presence of the static magnetic field also further improves the phase structure of the coating, so that the magnetic domain distribution is uniform and the hard phase inside the coating increases. Finally, the residual stress and tribological properties of the coating are also improved.