Crystal orientation and crystal structure of paramagnetic α-Al under a pulsed electromagnetic field

The intermittent electromagnetic fields with a large ∂ B / ∂ t can enhance the properties of ferromagnetic materials and significantly affect paramagnetic materials. In this study, the effect of a pulsed electromagnetic field on the crystal orientation of the primary phase and microstructure evolution of an Al–Zn–Mg–Cu alloy was investigated. A mathematical model was developed to describe crystal rotation under a pulsed electromagnetic field. The model predictions show that the magnetic energy difference generated by the magnetic anisotropy of the primary crystal produces primary phases with sizes of 225–100 μm to rotate into a preferred orientation. The lattice constant, the interplanar spacing, and the microstrain increase with the duty cycle of the pulsed magnetic field, especially for the (111) and (200) crystal planes. This study provides preliminary theoretical support for using pulsed electromagnetic fields to control the orientation and microscopic properties of materials.