Achieving Texture Randomization and Yield Anisotropy Reduction in As-Rolled Mg-Zn-Y-Zr Alloy by Multidirectional Impact Forging

Abstract

Multidirectional impact forging (MDIF) has been utilized to attain texture randomization and yield strength anisotropy reduction of as-rolled Mg-Zn-Y-Zr alloy. The forging results show the strong basal texture rapidly developed to be a random texture with multiple peaks and the corresponding texture intensity sharply decreased from 5.67 multiples of random distribution (mrd) to 2.05 mrd. Meanwhile, the initial coarse grains in ~113 μm were also effectively refined to ~2.3 μm. Expectedly, yield strength anisotropy also has been significantly reduced, i.e., the ratio of tensile yield strength between normal and rolling direction increased from 0.61 to 0.88. The yield anisotropy reduction is mainly attributed to the effective texture randomization and grain refinement promoted by {10-12} twinning and it induced recrystallization. This MDIF technique has a promising perspective to randomize the strong texture for rolled or extruded billets of Mg alloys.

Keywords: Texture randomization, Yield anisotropy reduction, Mg-Zn-Y-Zr alloy, Multidirectional impact forging, Twinning