Microstructure, texture modification and mechanical anisotropy of high strain rate rolled Mg–Ga alloy sheets

Microstructure, texture modification and mechanical anisotropy of the high strain rate rolled Mg–xGa alloys (x = 1, 2, 3 and 5, in wt%) were carefully investigated by EBSD, XRD, tensile testing, etc. The Ga addition can promote the transformation from the substructure to the recrystallized grains in the process of dynamic crystallization (DRX) so as to obtain the uniform microstructure and enhance the formation of twinning during deformation, which weakens the texture of the sheet and eventually forms the higher scatter texture. Moreover, the Mg–2Ga alloy shows the lowest texture intensity and thus exhibits the best combination of strength and plasticity and excellent plasticity, with the elongation-to-failure from 31.1 to 34.5% in three testing directions. The higher Ga content brings about the bigger work hardening index (n value) of the alloy sheet. The n value in the RD direction rises from 0.18 to 0.27 with the increasing Ga addition from 1 to 5%. The Mg–Ga alloys have very low plastic anisotropy and their plastic strain ratios are about 1. The Mg–2Ga alloy shows the lowest r value (1.07) and its ∆r value is 0.02. The wrought Mg–Ga alloys can achieve both high plasticity and low plastic anisotropy, which are promising for the industrial applications.