Tension-compression asymmetry of temperature dependencies in Mg rare-earth alloys

Abstract

To reveal the tension-compression asymmetry of temperature-dependency in Mg-RE alloys, uniaxial tensile and compression tests followed by microstructural characterizations were performed on a cast Mg-10Gd-3Y-0.5Zr (wt.%) alloy under various temperatures. The results show that this alloy exhibits anomalous temperature effects on mechanical properties (such as tensile strength and plasticity) during tension, while they are not observed during compression tests, demonstrating that the anomalous temperature effects exhibit loading path dependence. The tension-compression asymmetry of the anomalous temperature-dependency associated with variations in twinning. It is believed that these variations in twinning result from the interplay between the inhibitory effect of rare earth elements on twinning and the promoting effects of elevated temperature or a change in the loading path from tension to compression, with the loading path having a stronger promoting influence than the deformation temperature.

Keywords

• Rare-earth magnesium alloys
• Mechanical behavior
• Loading path
• Anomalous temperature and strain rate effects
• Twinning behavior