Compression behavior of magnesium-lithium alloy at room temperature
(1.Environmental Corrosion Center, Institute of Metal Research, Chinese Academy of Sciences,Shenyang 110016, China
2.Shenyang National Laboratory for Materials Science, Institute of Metal Research,Chinese Academy of Sciences, Shenyang 110016, China
3.辽宁省沈阳市科学院金属研究所材料环境腐蚀试验研究中心)
2.Shenyang National Laboratory for Materials Science, Institute of Metal Research,Chinese Academy of Sciences, Shenyang 110016, China
3.辽宁省沈阳市科学院金属研究所材料环境腐蚀试验研究中心)
Abstract: The mechanical properties of LA40 magnesium alloy were investigated under compression at room temperature. In the applied strain rate range from 1.33×10-4 s-1 to 6.66×10-4 s-1, this alloy shows positive strain rate sensitivity (SRS). Most importantly, the Portevin-Le Chatelier(PLC) effect which is an interesting and dominant feature in tensile tests disappears under compressive conditions. Only one twinning system is activated under tensile deformation, while at least two twinning modes are operative during compression. Additionally, the effect of dynamic strain aging (DSA), and the main mechanism for the onset of PLC phenomenon during tension, will be weakened because the strengthened obstructing influence of twins on solute atoms and the disappearance of PLC is inevitable.
Key words: compression; LA40 magnesium alloy; twinning; PLC effect