铸造工艺对自生Mg2Si/Al-20Si复合材料组织及性能的影响

采用熔体直接反应法制备了Mg2Si/Al-20Si复合材料,研究了不同浇注温度、冷却强度对该原位自生复合材料组织及性能的影响.结果表明,浇注温度为750 ℃时,复合材料中Mg2Si和初晶Si晶粒均匀细小,力学性能较好;在过低或过高的浇注温度时,复合材料中Mg2Si和初晶Si晶粒变粗大,力学性显著降低.同时,随着冷却强度的增加,复合材料的力学性显著增强.

Effects of Casting Process on Microstructure and Mechanical Properties of In-situ Mg2Si/Al-Si Composites

The Mg_2Si/Al-Si composites were prepared by direct melt reaction (DMR). Effects of pouring temperature and cooling rates on microstructure and mechanical properties of the composites were investigated. The results show that Mg_2Si particle and primary Si phase in the composites become fine and uniform with pouring at 750℃, and the mechanical properties of the composites are improved. The mechanical properties are greatly deteriorated as a result of the coarseness of Mg_2Si particle and primary Si phase in the composites with pouring at an under-lower or over-higher temperature. Meanwhile, with increasing in cooling rates, the mechanical properties of the composites are obviously improved.