论文部分内容阅读
本文利用定向凝固方法研究了Al2O3／Al－Si复合材料馆液中添加微量Ca对基体组织及Al2O3颗粒分布的影响．结果表明，Ca能够细化Al－Si合金基体的共晶Si，但Sr变质时添加Ca，Ca对Sr的共晶Si细化能力具有阻碍作用．Al－Si－Sr－Ca中Ca的变质阻碍作用可能是因为生成Ca－Sr－Si金属间化合物消耗了熔液中的Sr．单独添加Ca或Sr时，Al2O3颗粒都被凝固界面所排斥和推移，在固相中呈不均匀分布．但是Sr＋Ca添加时Al2O3颗粒能够在基体中均匀分布．
In this paper, the directional solidification method was used to study the effect of adding trace amount of Ca to the matrix structure and Al2O3 particle distribution in the Al2O3 / Al-Si composite material. The results show that Ca can refine the eutectic Si of Al-Si alloy matrix, but adding Ca and Ca to Sr deteriorate the eutectic Si refining ability of Sr. The deteriorating effect of Ca in Al-Si-Sr-Ca may be due to the fact that Sr in the melt is consumed by the formation of the Ca-Sr-Si intermetallic compound. When Ca or Sr alone was added, Al2O3 particles were repelled and pushed by the solidified interface, and were unevenly distributed in the solid phase. However, when Sr + Ca is added, Al2O3 particles can be uniformly distributed in the matrix.