热处理与锻造对原位Mg_2Si/Al复合材料组织及性能的影响

Effect of Heat Treatment and Forging on Microstructure and Property of In-stiu Mg_2Si/Al Composite

采用原位合法制备了4wt%Mg2Si/Al复合材料,研究了超塑性预处理Mg2Si对该复合材料组织和性能的影响。利用光学显微镜、X-射线衍射仪和扫描电镜等分析了该复合材料的物相和显微组织,并通过常温拉伸试验测试了其力学性能。结果表明:4wt%Mg2Si/Al复合材料经超塑性预处理后,Mg2Si形貌有了明显变化,由原来粗大的汉字状转变球状颗粒,尺寸由10μm减小到4μm;组织偏析现象和不平衡组织都得到极大改善。预处理后该复合材料的伸长率达到11.5%,比未预处理的材料提高了100%,塑性极大提高。

4wt%Mg2Si/Al composite was fabricated by melt direct reaction method. The effects of superplastic pretreatment on the performance and microstructure of the composite were investigated. The phase composition of the composite was investigated by OM, XRD, SEM and EDS. The mechanical properties of the composite were researched by room temperature extrude. The results indicate that：after superplastic pretreatment, the morphology of Mg2Si has changed a lot. The shape changes from dendrite into sphericity, and the average size of second phase particles reduces from 10 p^m to 4 Ixm. The segregation and unbalanced microstructure improves. The tensile elongation of the composite after superplastic pretreamaent is 11.5%, increasing by 100% than that of the samples before treatment which means that the plasticity improves a lot.