【摘要】 在AZ91镁合金基础上添加不同含量的混合稀土 (MM) ,对其铸态和固溶时效的组织及性能进行了研究。结果表明 ,MM显著改变AZ91合金的铸态组织 ,使Mg17Al12 相细化 ,并出现针状相 ,从而使硬度、强度提高 ,但冲击韧度值及伸长率下降 ;进一步的固溶时效证明该针状相并不固溶于基体中 ;MM的加入 ,推迟了AZ91的时效硬化过程。更多还原

【Abstract】 Effects of MM on the microstructure and properties of as cast and heat treated AZ91 Mg alloy were studied. The results showed that MM can improve significantly as cast microstructure of AZ91 Mg alloy, refining Mg 17 Al 12 phase and acicular phase occurred so as to increase in hardness and strength and decrease in impact toughness and elongation. During further solid solution heat treatment, the acicular phase is un dissolved in matrix. The ageing process of AZ91 Mg alloy was postponed with MM addition.更多还原