A modified Johnson-Cook constitutive relationship for a rare-earth containing magnesium alloy
来源期刊：Journal of Rare Earths2013年第12期
论文作者：F.A.Mirza 陈道伦 李德江 曾小勤
文章页码：1202 - 1207
摘 要：Lightweight magnesium alloy has recently attracted a considerable interest in the automotive and aerospace industries to improve fuel efficiency and reduce CO2emissions via the weight reduction of vehicles.Rare-earth（RE）element addition can remarkably improve the mechanical properties of magnesium alloys through weakening crystallographic textures associated with the strong mechanical anisotropy and tension-compression yield asymmetry.While the addition of RE elements sheds some light on the alteration in the mechanical anisotropy,available information on the constitutive relationships used to describe the flow behavior of RE-containing magnesium alloys is limited.To establish such a constitutive relationship,uniaxial compressive deformation tests were first conducted on an extruded Mg-10Gd-3Y-0.5Zr（GW103K）magnesium alloy at the strain rates ranging from 1×10–1to 1×10–4s–1at room temperature.A modified Johnson-Cook constitutive equation based on a recent strain hardening equation was proposed to predict the flow stresses of GW103K alloy.Comparisons between the predicted and experimental results showed that the modified Johnson-Cook constitutive equation was able to predict the flow stresses of the RE-containing magnesium alloy fairly accurately with a standard deviation of about 1.8%.
F.A.Mirza1，陈道伦1，李德江2，曾小勤2
1. Department of Mechanical and Industrial Engineering,Ryerson University2. The State Key Laboratory of Metal Matrix Composites,School of Materials Science and Engineering,Shanghai Jiao Tong University
摘 要：Lightweight magnesium alloy has recently attracted a considerable interest in the automotive and aerospace industries to improve fuel efficiency and reduce CO2emissions via the weight reduction of vehicles.Rare-earth（RE）element addition can remarkably improve the mechanical properties of magnesium alloys through weakening crystallographic textures associated with the strong mechanical anisotropy and tension-compression yield asymmetry.While the addition of RE elements sheds some light on the alteration in the mechanical anisotropy,available information on the constitutive relationships used to describe the flow behavior of RE-containing magnesium alloys is limited.To establish such a constitutive relationship,uniaxial compressive deformation tests were first conducted on an extruded Mg-10Gd-3Y-0.5Zr（GW103K）magnesium alloy at the strain rates ranging from 1×10–1to 1×10–4s–1at room temperature.A modified Johnson-Cook constitutive equation based on a recent strain hardening equation was proposed to predict the flow stresses of GW103K alloy.Comparisons between the predicted and experimental results showed that the modified Johnson-Cook constitutive equation was able to predict the flow stresses of the RE-containing magnesium alloy fairly accurately with a standard deviation of about 1.8%.
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