半固态Al-6.6%Si合金的变形行为

来源期刊：中国有色金属学报2000年第z1期

论文作者：郭钧 丁志勇 谢水生 黄声宏

文章页码：115 - 119

关键词：半固态； Al合金； 变形

Key words：semi-solid； aluminum alloy； deformation

摘    要：分别对常规铸造Al-6.6%Si合金和电磁搅拌制备的半固态Al-6.6%Si合金试样进行了压缩实验 ,分析了它们的应力—应变关系和组织变化。结果表明 ,半固态Al-6.6%Si合金液固两相区压缩变形可分为触变流动初始阶段和稳定触变流动两个阶段。在触变流动初始化阶段 ,应力从零急剧增大到最大值 ,并在这个最大值上保持一段时间。在稳定触变流动阶段 ,随应变增加 ,应力缓慢下降 ,整个过程应力都大大低于常规铸造Al-6.6%Si合金压缩变形时应力。半固态合金在液固态两相区压缩变形后 ,其初生相微粒仍保持为球状 ,并且试样各处变形均匀。同时 ,对半固态合金变形中的初生相微粒簇现象和液固分离现象也进行了讨论。

Abstract: Compression tests on Al-6.6%Si alloy normally cast and electro-magnetically stirring casted were carried out using a Gleeble-1500 dynamic material testing machine. The microstructure and relationship between the true stress and the true strain for the deformed semi-solid Al-6.6%Si alloy were analyzed. Results show that the deformation process of semi-solid Al-6.6%Si alloy may be divided into two stages: an initial thixotropic stage and a steady thixotropic stage. In the initial stage, the stress increases from zero to a maximum and keeps at this level for a short time. In the steady stage, the stress gradually decreases. The compression stress of semi-solid Al-6.6%Si alloy is much lower than that of normally casted Al-6.6%Si alloy. The primary grains remain spheric after doformation and the deformation is even. In addition, evolution of clusters of primary grains and separation between solid and liquid during deformation were discussed.