The effect of twinning and detwinning on the mechanical property of AZ31 extruded magnesium alloy during strain-path changes

• The detwinning behavior occurred during inverse tension test.
• Tension yield strength decreased as the increase of pre-compression levels.
• The ductility was improved by pre-compression for {1 0 −1 2} twins.
• Detwinning was restrained during compression tests in pre-stretch samples.
• Compression yield strength increased as pre-stretch levels increasing.

In order to investigate the effect of twinning–detwinning on the mechanical properties of AZ31 extruded magnesium alloy pre-compression and pre-stretch deformation were conducted along extrusion direction (ED) at 1%, 3%, 5% strain levels. After pre-strain, the strain-path was inverted by performing tensile or compressive tests at room temperature. Results showed that the detwinning behavior occurred during the inverse tension after the pre-compression. Although due to the aforementioned effect the tensile yield strength decreased, by increasing the pre-compressive levels both fracture elongation and peak strength improved. In the inverse compressive tests after pre-stretch the {1 0 −1 2} twinning was restrained and the volume fraction of twins decreased, leading to the improvement of yield strength by increasing in pre-stretching levels.