Influence of Ge content on the microstructure, phase formation and microhardness of hypereutectic Al–Si alloys
Influence of Ge content on the microstructure, phase formation and microhardness of hypereutectic Al–Si alloys
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DOI：
10.1016/j.jallcom.2013.09.180
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发表时间：
2014-02
影响因子：
6.2
通讯作者：
Yongrui Zhang;Tong Gao;Xiangfa Liu
中科院分区：
文献类型：
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作者：
Yongrui Zhang;Tong Gao;Xiangfa Liu
本文研究了Al-18 Si-xGe三元合金的相组成。结果表明，除α-Al外，合金中还存在初晶Si、初晶Ge、共晶Si和共晶Ge，这取决于合金成分的不同。研究了Ge含量对Al-18 Si合金显微组织、相形成和显微硬度的影响。结果表明，Ge的加入改善了Al-18 Si合金的显微组织，在初生相和共晶相中Ge和Si都有一定程度的相互替代。Al-18 Si-xGe合金中Ge含量的增加导致初晶Si中Ge含量的增加。在共晶组织中还存在连续的Si和Ge成分过渡区。结合显微组织，利用差示扫描量热仪（DSC）分析了Al-18 Si-xGe合金的凝固过程。此外，随着Ge含量的增加，初晶Si的显微硬度先减小后增大，而共晶区的显微硬度和块体合金的宏观硬度均呈单调增加的趋势。
In this study, composition of the phases in ternary Al–18Si–xGe alloys was investigated. It was found that except α-Al, there may form primary Si, primary Ge, eutectic Si and eutectic Ge, depending on different composition of the alloys. The influence of Ge content on the microstructure, phase formation and microhardness in Al–18Si alloy was investigated. Experimental results show that the introduction of Ge in Al–18Si alloy can modify the microstructures, and Ge and Si can replace with each other to some extent in both primary and eutectic phases. The increase of Ge addition level in Al–18Si–xGe alloys leads to an increase of Ge content in primary Si. There also exist continuous composition transition zones for Si and Ge in eutectic structure. Combining with the microstructures, the solidification process of the Al–18Si–xGe alloys was analyzed by differential scanning calorimeter (DSC). Besides, with the increase of Ge content in the alloys, the microhardness of primary Si decreases first and then increases, while the microhardness of the eutectics and macrohardness of the bulk alloys exhibit monotone increase.