1,绪言镁的比重为铝的2/3,在实用合金中镁最轻,它是一种比强度(强度/比重)良好的金属。工业用镁合金一般都含有Al、Zn、Mn、Zr等合金成分。为了提高强度和抗腐蚀性并进一步增强耐热性,合金中含有稀土元素和Th,它是衰减能力良好的合金。表1示出镁合金的物理性能,表2示出主要镁合金的成分和机械性能。镁合金和其它金属一样,用电弧焊接法、 INTRODUCTION The specific gravity of magnesium is 2/3 of that of aluminum. Magnesium is the lightest in practical alloys. It is a metal of good specific strength (strength / specific gravity). Industrial magnesium alloys generally contain Al, Zn, Mn, Zr and other alloy components. In order to improve the strength and corrosion resistance and further enhance the heat resistance, the alloy contains rare earth elements and Th, which is a good damping ability of the alloy. Table 1 shows the physical properties of the magnesium alloy, and Table 2 shows the composition and mechanical properties of the main magnesium alloy. Magnesium alloy, like other metals, arc welding method,