中文摘要：

AM60B 镁合金的微观结构和腐蚀行为，由两个生产了高压死扔(HPDC ) 并且超级真空死扔(SVDC ) 处理，被 X 光检查衍射(XRD ) 的联合调查，扫描电子显微镜学(SEM ) ，和慢正电子微笑技术。XRD 证实在腐蚀的早阶段期间在合金的表面上扔的钙碳酸盐(CaCO3 ) ，和免职 CaCO3 评价因为有腐蚀时间的 SVDC 比 HPDC 的慢。SEM 观察发现在 SVDC 合金的皮肤表面的阶段比 HPDC 合金的有更大的体积部分和更连续的分发，导致在在一样的腐蚀时间的 SVDC 合金的表面上扔的 CaCO3 的更低的体积部分。拓宽测量的慢正电子横梁 Doppler 表明表面腐蚀层的厚度与腐蚀时间增加了。与 HPDC 合金相比，为 SVDC 合金的厚度的增加率更慢，它暗示那 SVDC 合金比 HPDC 合金展出了一个更好的腐蚀电阻。

英文摘要：

The microstructures and corrosion behavior of AM60B magnesium alloys, produced by both high-pressure die casting （HPDC） and super vacuum die casting （SVDC） processes, were investigated by a combination of X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and slow positron beam technique. XRD confirmed that calcium carbonate （CaCO3） deposited on the surface of alloys during the early stages of corrosion, and the deposition rate of CaCO3 for SVDC with corrosion time was slower than that of HPDC. SEM observation found that the -phases in the skin surface of SVDC alloy had a greater volume fraction and more continuous distribution than that of HPDC alloy, leading to lower volume fraction of CaCO3 deposited on surface of SVDC alloy for the same corrosion time. The slow positron beam Doppler broadening measurement revealed that the thickness of surface corrosion layer increased with corrosion time. Compared with HPDC alloy, the increase rate of thickness for SVDC alloy is slower, which implied that SVDC alloy exhibited a better corrosion resistance than HPDC alloy.