During the material preparation process, the magnetic field can act with high intensity energy on the material without contact and affect its microstructure and properties. This non-contact processing method, which can change the microstructure and properties of material without affecting the shape and size of products, has become an important technical means to develop new materials and optimize the properties of materials. It has been widely used in scientific research and industrial production. In recent years, the magnetic field assisted processing of difficult-to-deform materials or improving the performance of complex and precision parts has been rapidly and widely concerned by scholars at home and abroad. This paper reviews the research progress of magnetic field regulating the microstructure, and properties of solid metal materials. The effects of magnetic field-assisted heat treatment, magnetic field assisted stretching, and magnetic field independent treatment on the microstructure and properties of solid metal materials are introduced. The mechanism of the magnetic field effect on the properties of metal materials is summarized, and future research on the magnetic field effect on solid metal has been prospected.

Commercial oxygen-free copper sheets were cold-rolled with reduction rates ranging from 20% to 87% and annealed at 400, 500 and 600 °C. The microstructure and texture evolution during the cold-rolling and annealing processes were studied using optical microscopy (OM), scanning electron microscopy (SEM) and electron back-scattered diffraction (EBSD). The results show that the deformation textures of {123} (S), {112} (Copper) and {110} (Brass) were continuously enhanced with the increase in cold-rolling reduction. The orientations along the α-oriented fiber converged towards Brass, and the orientation density of β fiber obviously increased when the rolling reduction exceeded 60%. The recrystallization texture was significantly affected by the cold-rolling reduction. After 60% cold-rolling reduction, Copper and S texture components gradually decreased, and the {011} recrystallization texture component formed with the increase in annealing temperature. After 87% cold-rolling reduction, a strong Cube texture formed, and other textures were inhibited with the increase in annealing temperature. The strong Brass and S deformation texture was conducive to the formation of a strong Cube annealing texture. The density of the annealing twin boundary decreased with the increase in annealing temperature, and more annealing twin boundaries formed in the oxygen-free copper sheets with the increase in cold-rolling reduction.

The effect of a pulsed magnetic field on the microstructure of a QAl9-4 aluminium bronze alloy was studied in this work. It was found that the dislocation density, grain boundary angle, and microhardness of the alloy significantly changed after the magnetic field treatment with a peak magnetic induction intensity of 3T, pulse duration of about 100 us, pulse interval of 10 s, and pulse time of 360. EBSD was used to test the KAM maps of the alloy microzone. It was found that the alloy’s dislocation density decreased by 10.88% after the pulsed magnetic field treatment; in particular, the dislocation in the deformed grains decreased significantly. The quantity of dislocation pile-up and the degree of distortion around the dislocation were reduced, which decreased the residual compressive stress on the alloy. Dislocation motion caused LAGB rotation, which reduced the misorientation of adjacent points inside the grain. The magnetic field induced the disappearance of deformation twins and weakened the strengthening effect of twins. The microhardness test results show that the alloy’s microhardness decreased by 8.06% after pulsed magnetic field treatment. The possible reasons for the magnetic field effect on dislocation were briefly discussed. The pulsed magnetic field might have caused the transition to the electronic energy state at the site of dislocation pinning, which led to free movement of the vacancy or impurity atom. The dislocation was easier to depin under the action of internal stress in the alloy, changing the dislocation distribution and alloy microstructure.

The commercial oxygen-free copper sheets were cold-rolled with reduction rates ranging from 20% to 87% reduction rate and annealed at 400, 500 and 600 °C. The microstructure and texture evolution during cold-rolling and annealing processes were studied using optical microscopy (OM), the scanning electron microscopy (SEM) and the electron back-scattered diffraction (EBSD). The results show that the deformation textures of {123} (S) , {112} (Copper) and {110} (Brass) were continuously enhanced with the increase of cold-rolling reduction. The orientations along the α-oriented fiber converged towards Brass and the orientation density of β fiber obviously increased when the rolling reduction exceeded 60%. The recrystallization texture was significantly affected by the cold-rolling reduction. After 60% cold-rolling reduction, Copper and S textures components gradually decreased and {011} recrystallization texture component formed with the increase of annealing temperature. After 87% cold-rolling reduction, a strong Cube texture formed and other textures were inhibited with the increase of annealing temperature. The strong Brass and S deformation texture was conducive to the formation of a strong Cube annealing texture. The density of annealing twin boundary decreased with the increase of annealing temperature, and more annealing twin boundaries formed in the oxygen-free copper sheets with the increase of cold rolling reduction.

To improve the mechanical properties and wear resistance of QAl9-4 aluminum bronze alloy parts of high-speed rail brake calipers, the solid aluminum bronze alloy was treated with a pulsed magnetic field in which the magnetic induction intensity was 3T at room temperature. After that, a tensile test and a friction and wear test were carried out on the alloy. The results indicate that the magnetic field promotes the movement of low-angle grain boundaries less than 2° and splices to form subcrystals or fine crystals, which reduces the mean grain size of the alloy. The disordered dislocation changed into a locally ordered dislocation line, the dislocation distribution became uniform, and the dislocation density increased, which simultaneously improved the alloy’s tensile strength and elongation. The elongation increased by 10.2% compared with that without the magnetic field. The increase in strength can provide strong support for the wear-resistant hard phase, and the enhancement of plasticity can increase the alloy’s ability to absorb frictional vibration. Therefore, it was hard for cracks to form and extend, and the specimen’s average friction coefficient was reduced by 22.05%. The grinding crack width and depth decreased, the wear debris became more uniform and fine, and the alloy’s wear resistance increased.