凝固条件对高硅铝合金组织的影响

The Effect of Solidification Condition to Al-Si Hypereutectic Alloys

过共晶铝硅合金中的硅相晶粒粗大并且有尖锐的棱角,严重的削弱了合金的机械性能,通常采用变质处理工艺来改善这一现象。目前,很多研究表明硅相变质的机理主要是孪晶凹谷机制,但是变质效果实际上是与凝固条件有关系的,通过改善凝固条件,可以促进变质效果。本文研究对象为高硅铝硅合金,在加入不同变质剂条件下,研究了不同凝固条件下的组织形态,并使用透射电镜对组织进行了分析。

Primary Si phases exist in AI-Si Hypereutectic which harm the mechanical performance because of crassitude and edges. The modification technology is always adopted to improve its performance. Study demonstrates tile mechanism of silicon is TPRE mechanism but the solidification condition affectes the result of modification.The suitable solidification condition can improve the resull of modification.The paper researches the structure of hypereutectic AI-Si alloy in the condition of the different modification and solidification and uses the TEM to analyze the structure of the alloy.