Improving the plastic homogeneity of a magnesium alloy by introducing high volume fraction of twins during ambient extrusion

Abstract

Abstract Ambient extrusion was conducted to impart different strains on an AZ31 magnesium alloy. Lamellar twins were observed in the strained samples, and twin density increased with strain. Uniaxial tensile tests were conducted on the extruded samples with different strains. An abnormal raise in elongation was observed at higher strains with high volume fraction of 10 1 ¯ 1 twins. With the increase of extrusion strain, the elongation decreased initially and then got increased from a critical strain e c r without any sacrifice in strength. The basal texture was weakened due to twinning related crystal lattice rotation. Basal slip was thus easier to activate inside the twinned region to accommodate the plastic strain leading to an increase in elongation. The special twinning skeleton structure was expected to sustain a high stress to resist the necking.