镁基准晶对AZ91合金组织与性能的影响  

Influence of Mg-based Quasi-crystals on Microstructure and Mechanical Properties of AZ91 Alloy

作　　者：张金山[1] 王晓明[1] 裴利霞[1] 杜宏伟[1] 严杰[1] 田爱环[1] 梁伟[1] 

机构地区：[1]太原理工大学材料科学与工程学院,山西太原030024

出　　处：《铸造》2007年第7期687-690,共4页Foundry

基　　金：国家自然科学基金资助项目(50571073);山西省自然科学基金资助项目(20051052);太原市大学生专项(07010713)。

摘　　要：通过采用扫描电子显微镜、能量散射光谱和透射电镜等分析手段,研究了两种不同成分和形态的准晶中间合金对AZ91合金显微组织与力学性能的影响。结果表明,在AZ91合金中加入镁基准晶中间合金后,在其铸态合金的显微组织中除α-Mg基体相、β-Mg17Al12相外还出现了弥散分布在α-Mg内部和晶界附近的高热稳定的准晶相;由于加入的准晶中间合金中准晶相的形貌不同,遗传效应不同,所以其细化效果也存在差异。经准晶强化的AZ91合金常高温拉伸强度明显提高,但用MZYM中间合金对力学性能的提高要远远大于用MZY合金。这为镁基合金的强化提供一条新途经。Effect of Mg-based quasi-crystals with different chemical compositions and morphologies on microstructure and mechanical properties of AZ91 alloy has been investigated using XRD, SEM, EDS, TEM and a hydraulic universal material testing machine. The results show that the addition of Mg-based quasi-crystals into AZ91 alloy results in dispersive distribution of high thermal-stable quasi-crystal phase either in α-Mg matrix or on the grain boundaries, which coexist with β-Mg12Al17 phase and α-Mg matrix. Grain-refining efficiency on the α-Mg matrix differs due to various morphologies of the quasi-crystal particles introduced into AZ91 alloy. Room and elevated temperature tensile strength of AZ91 alloy have been obviously improved after the reinforcement of quasi-crystals. However, Mg-Zn-Y-Mn （MZYM） quasi-crystals have more effective strengthening effects on AZ91 alloy than Mg-Zn-Y （MZY） quasi-crystals.

关 键 词：镁基准晶相 形貌 AZ91合金 遗传效应 复合强化 常规铸造 

分 类 号：TG146.22[一般工业技术—材料科学与工程] TG113[金属学及工艺—金属材料]