Mechanism and application of mechanical property improvements in engineering materials by pulsed magnetic treatment: A review

Pulsed magnetic treatment (PMT) has been adopted as an effective strengthening method for engineering materials and components in recent years, and the development of its application depends on the comprehensive understanding of the nature of PMT. The deep mechanism was thought initially to be the magnetostrictive effect, while further investigation found that the magnetic field could lead to the change of the defect states in the crystal, which is called the magnetoplastic effect. Due to the complexity of the engineering materials, manifestations of the magnetoplastic effect become more diverse, and they were reviewed in the form of microstructure homogenization and interfacial stabilization. Further, the mechanism of the magnetoplastic effect was discussed, focusing on the changes in the spin states under the external magnetic field. Microstructure modifications could also alter material performances, especially the residual stress, plasticity, and fatigue properties. Therefore, PMT with specific parameters can be utilized to obtain an ideal combination of microstructure, residual stress, and mechanical properties for better service performance of different mechanical parts, and its applications on machining tools and bearings are perfect examples. This work reviews the effect of PMT on the microstructure and properties of different materials and the mechanism, and it also summarizes the fundamental applications of PMT on essential mechanical parts.