The effect of current direction (CD) on the microstructural evolution and mechanical properties of a Cu–Zn binary phase (α + β) alloy during the primary process of phase transformation induced by electric current pulses (ECP) treatment was investigated. To clarify the effect of CD, the samples were prepared with different angles between the CD and rolling direction (RD) from 0° to 90°. Results showed that not only the microstructural evolution but also the corresponding mechanical properties all had a saddle point in the sample with the angle 45°. Analyzed from the mechanical properties, it could be found that the anisotropic of the materials becomes stronger due to the application of ECP. An important finding is that by changing the angles between the CD and the RD, a novel and effective approach to control the phase transformation process could be provided.

The variant selection from the parent α phase to the product β phase during the enhanced phase transformation induced by the electric current pulses (ECPs) was investigated in a Cu–Zn alloy. The electron backscatter diffraction results showed that the crystallographic variant selection was not only across those prior α/α grain boundaries, but also within the α grain interior, and it implied that the nucleation of the β phase on the up-transformation obeyed a preferred orientation selection. Further analysis revealed that the orientation relationship between the α phase and the β phase variants nucleated from the α phase was close to 44.3° about <114>, which clearly described the rotation axes and the misorientation angles in terms of an axis/angle description when the high temperature phase nucleated from the matrix. Therefore, the ECP treatment would provide a new promising and convenient method to investigate the variant evolution on the up-transformation.