Effect of Fe content on the tribological properties of Ni60 coatings applied by pulsed magnetic field assisted supersonic plasma spraying

In order to study the effect of magnetic field on the spraying process, a thermal spraying technique of ferromagnetic metal powder assisted by pulsed magnetic field is presented. The Ni60 coating with different Fe content was prepared by pulsed magnetic field assisted supersonic plasma spraying. This process can improve the microstructure, porosity, mechanical properties and tribological properties of the coating. In this paper, a diagram depicting the mechanism for coating formation by pulsed magnetic field assisted spraying was prepared according to the test results for the coatings. We found that the pulsed magnetic field formed at the edge of the poles, and, compared with the Ni base material, the Fe phase material was easily attracted by the magnetic poles, which accelerated its downward movement. During this downward movement, a mixing effect developed within the coating that decreased the coating porosity, made the Cr strengthening phase more uniform, and, as the matrix provided many nucleation sites, further promoted the production of amorphous nanocrystalline phases. Finally, the service performance of the coatings was continuously improved. This process provides a new approach to the design and development of advanced coatings, and it shows great promise for applications in next-generation ferromagnetic metal-based coatings.