Simultaneously Improving Ductility and Stretch Formability of Mg-3Y Sheet via High Temperature Cross-Rolling and Subsequent Short-Term Annealing

Abstract

In this work, Mg-3Y sheet was prepared by high temperature cross-rolling and subsequent short-term annealing. The effect of annealing on microstructure, texture, mechanical properties, and stretch formability of Mg-3Y sheet was primarily investigated. Micro-nano size coexistence of β-Mg24Y5 phases can be well deformed with matrix. The as-rolled Mg-3Y sheet exhibited a homogeneous deformation microstructure consisting of deformed grains with extensive kink bands and dispersed β-Mg24Y5 phases. A double peak texture character appeared in as-rolled Mg-3Y sheet with a split of the texture peaks of about ±20° tilted to rolling direction. After annealing, the as-annealed Mg-3Y sheet presented complete static recrystallized (SRXed) microstructure consisting of uniform equiaxed grains. The texture orientation distribution was more dispersed and a weakened multiple-peak texture orientation distribution appeared. In addition, the maximum intensity of basal plane decreased from 5.2 to 3.1. The change of texture character was attributed to static recrystallization (SRX) induced by kink bands and grain boundaries. The as-annealed Mg-3Y sheet with high Schmid factor (SF) for basal <a> slip, prismatic <a> slip, pyramidal <a> slip, and pyramidal <c+a> slip exhibited high ductility (~25.6%). Simultaneously, enhanced activity of basal <a> slip and randomized grain orientation played a significant role in decreasing anisotropy for the as-annealed Mg-3Y sheet, which contributed to the formation of high stretch formability (~6.2 mm) at room temperature.

Effect of annealing on AZ31 magnesium alloy on MAO coatings

“…Zhang et al 6 showed that the yield strength and ultimate tensile strength of Mg–2Ag alloy increased significantly after multi-pass hot rolling treatment, and the elongation also changed with the increase of rolling passes. Wang et al 7 have shown that compared with pure Mg, the ductility and stretch formability of Mg–3Y alloy can be improved simultaneously through cross-rolling at high temperatures and subsequent annealing. Li et al 8 have shown that under current densities below 30 A/dm 2 , the corrosion resistance and photo-thermal properties of the Mg–3Zn–0.2Ca alloy micro-arc oxidation (MAO) coating continue to improve as the current density increases.…”

Research Progress in High-Performance Magnesium Alloy and Its Applications

“…A Mg alloy rolling sheet usually exhibits a strong basal texture and bad formability. Wang et al [5] applied multipass high-temperature cross-rolling with interpass annealing to Mg-3Y alloy. The Mg-3Y alloy sheet presented a complete SRXed microstructure consisting of uniform equiaxed grains and a weakened multiple-peak texture.…”