【摘要】 研究了挤压铸造AZ91D镁合金在不同热处理状态下的显微组织、力学性能以及厚度对镁合金试样力学性能的影响。结果表明,挤压铸造AZ91D镁合金铸态显微组织主要由基体α-Mg和在晶内及晶界上分布的β-Mg17Al12相组成,经固溶处理后得到单相α-Mg固溶体组织,而且在α-Mg晶粒内部也出现了少量颗粒状析出物,经固溶时效处理后β-Mg17Al12相再一次在α-Mg晶内和晶界析出,且晶粒变得更加细小;挤压铸造AZ91D镁合金的硬度、屈服强度、抗拉强度随着试样厚度的增加而减小,而伸长率随着试样厚度的增加而增加。更多还原

【Abstract】 Microstructure and mechanical properties of squeeze casting AZ91 Dalloy under different heat treatment conditions were investigated,and effects of wall thickness on mechanical properties were also discussed.The results show that microstructure of squeeze casting AZ91 Dalloy consists of primaryα-Mg matrix andβ-Mg17Al12 phase which is mainly present in the matrix and grain boundaries.Single phaseα-Mg solid solution is observed after solid solution treatment,and a few granular precipitates are distributed insideα-Mg matrix.After solid solution aging treatment,β-Mg17Al12 phase is distributed at insideα-Mg matrix and grain boundaries again.Moreover,theβ-Mg17Al12 phase is present in form of finer particles.The hardness,yield strength and tensile strength of squeeze casting AZ91 Dalloy are decreased while elongation is increased with the increase of wall thickness.更多还原