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在真空感应炉中氩气保护下制备材料 ,采用OM ,SEM ,EDAX和XRD及拉伸试验 ,研究分析了硅对原位反应自生Mg2 Si/ZM5复合材料铸态显微组织和性能的影响规律。结果表明 ,反应添加物Si在ZM5合金中形成了高熔点、高硬度的Mg2 Si强化相 ,明显地提高了材料的室温与高温强度 ,如Si的质量分数为 1.5 %时 ,室温抗拉强度与屈服强度提高幅度分别可达 2 0 .1%和 61.5 % ,Si的质量分数为 1.0 %时 ,高温抗拉强度与屈服强度提高幅度分别可达 14 .9%和 2 5 .7% ;Mg2 Si相的形貌随着硅含量的不同而变化 ,如Si的质量分数为 0 .5 %时 ,主要生成细小短棒状或片状共晶Mg2 Si相 ,Si的质量分数大于1%时 ,则出现了粗大块状或汉字状初生Mg2 Si相和片状或短棒状的共晶Mg2 Si相 ;由于所生成的Mg2 Si相本身是一种脆性相 ,使得该材料呈现出解理断裂 ,降低了材料的塑性。
The effects of silicon on the microstructure and properties of in-situ Mg2Si / ZM5 composites were investigated by OM, SEM, EDAX, XRD and tensile tests under argon atmosphere in a vacuum induction furnace. . The results show that the reaction additive Si forms a high melting point and high hardness Mg2Si phase in ZM5 alloy, and obviously increases the room temperature and high temperature strength of the material. For example, when the mass fraction of Si is 1.5%, the tensile strength at room temperature The yield strength increases by 20.1% and 61.5%, respectively. When the mass fraction of Si is 1.0%, the tensile strength and yield strength increase by 14.9% and 25.7% Phase morphology changes with the silicon content varies, such as Si mass fraction of 0.5%, the main generation of small short rod-shaped or flaky eutectic Mg2 Si phase, Si mass fraction of more than 1%, then appear Coarse or kong-shaped primary Mg2 Si phase and flaky or short rod-shaped eutectic Mg2 Si phase; due to the Mg2 Si phase itself is a brittle phase, making the material showing cleavage fracture, reducing the material Plasticity.