中文摘要：

通过铜模铸造制备快速凝固的AZ91HP镁合金.利用失重法及动电位极化曲线研究了常规铸造AZ91HP和快速凝固AZ91HP镁合金样品在NaCl腐蚀介质中的耐腐蚀性能;通过金相显微镜（OM）、扫描电镜（SEM）及X射线衍射（XRD）分析了腐蚀后合金微观组织及相结构.结果表明,快速凝固的AZ91HP镁合金具有更好的耐腐蚀性能.其主要原因是经快速凝固工艺后：①β-Mg17Al12相近似连续地分布于细小的α-Mg晶界上;②合金的元素分布更加均匀;③合金显微缩松减少.

英文摘要：

Copper-mould casting process was utilized to prepare rapid solidification（RS） alloy samples.The corrosion properties of conventional casting（CC） AZ91HP alloy and rapid solidification（RS） alloy in different NaCl solutions were studied by static weight loss test and polarization curve measurement.Microstructure and phase constituent of magnesium alloys were investigated utilizing optical microscopy（OM）,scanning electronic microscopy（SEM）,X-ray diffractometry（XRD）.The results show that RS alloy had better corrosion resistance.This is attributed to a combination of a more continuous β-Mg17Al12 phase distribution around finer a grains,chemical homogeneity of α-Mg phase,and less porosity.