Deformation mechanism of fine grained Mg–7Gd–5Y–1.2Nd–0.5Zr alloy under high temperature and high strain rates

• Main Authors: Wanru Tang, Zheng Liu, Shimeng Liu, Le Zhou, Pingli Mao, Hui Guo, Xiaofang Sheng
• Format: Article
• Language: English
• Published: KeAi Communications Co., Ltd. 2020-12-01
• Series: Journal of Magnesium and Alloys
• Subjects: Mg–7Gd–5Y–1.2Nd–0.5Zr magnesium alloy; High strain rate deformation; Local deformation mechanism
• Online Access: http://www.sciencedirect.com/science/article/pii/S2213956720300839

Fine grained Mg–7Gd–5Y–1.2Nd–0.5Zr alloy was investigated by dynamic compression tests using a Split Hopkinson Pressure Bar under the strain rates in the range 1000–2000 s − 1 and the temperature range 293–573 K along the normal direction. The microstructure was measured by optical microscopy, electron back-scattering diffraction, transmission electron microscopy and X-ray diffractometry. The results showed that Mg–7Gd–5Y–1.2Nd–0.5Zr alloy had the positive strain rate strengthening effect and thermal softening effect at high temperature. The solid solution of Gd and Y atoms in Mg–7Gd–5Y–1.2Nd–0.5Zr alloy reduced the asymmetry of α-Mg crystals and changed the critical shear stress of various deformation mechanisms. The main deformation mechanisms were prismatic slip and pyramidal 〈a〉 slip, {102} tension twinning, and dynamic recrystallization caused by local deformation such as particle-stimulated nucleation.