純マグネシウムおよび Mg-Ca 合金の微小ひずみ領域における力学的挙動

抄録

  Tensile response at low strains and damping capacity were characterized in pure magnesium and Mg-1 mass%Ca alloy with the aim of revealing the effect of extrusion process and Ca addition. The damping capacity of extruded magnesium and solution treated Mg-1 mass%Ca alloy was lower than that of cast magnesium in the strain range examined. The proportional limit in the stress-strain relation of extruded magnesium and solution treated Mg-1 mass%Ca alloy was higher than that of cast magnesium. For all materials examined, the proportional limit corresponded to the critical strain, above which damping capacity begins to increase with strain. This suggests that dislocations breaking away from weak pinning points such as impurity/solute atoms causes the deviation from linearity in the stress-strain relation.