Fatigue/wear mechanism–property of Ni-based composite coatings by pulsed magnetic field post-treatment

In numerous engineering domains such as aerospace, mechanical manufacturing, and the automotive industry, many components rely on surface coatings to withstand service damage under harsh operating conditions. Owing to the precise configuration design of components, non-contact post-treatment approaches are among the crucial means to ameliorate the fatigue failure of coatings. Among them, a high-intensity pulsed magnetic field post-treatment has been widely applied due to its advantages such as non-contact, high energy, and high efficiency. Therefore, this paper adopts a combination of simulation and experiment to evaluate the influence of this technology on the microstructure and magnetic domain distribution, mechanical properties, and service performance of the coating. After post-treatment with a gradient high-intensity pulsed magnetic field, the tribological coefficient of the coating decreased from 0.57 to 0.46. The wear resistance improved positively with the change of the gradient magnetic field. The fatigue performance showed the same trend, and the optimal post-treatment process increased the fatigue life of the coating by 128.78%. The main mechanism is as follows: Post-treatment with pulsed magnetic fields improves the distribution of magnetic domains within the coating, causing many dislocations to be generated and concentrated at the grain boundaries, which inhibits crack propagation and promotes the transformation of residual compressive stress. Ultimately, it enhances the comprehensive service performance of the sample.