熔体过热处理对亚共晶Al-Si合金凝固特性和组织的影响  

Effect of Melt Superheating on the Solidification Behavior and Structure of Hypoeutectic Aluminum-silicon Alloy

作　　者：常芳娥[1] 高玉社[1] 坚增运[1] 周晶[1] 郑超[1] 吕士勇[1] 

机构地区：[1]西安工业大学材料与化工学院,西安710032

出　　处：《西安工业大学学报》2009年第2期148-151,共4页Journal of Xi’an Technological University

基　　金：国家自然科学基金(50571076;50671075);国家973项目(2006CB605202)

摘　　要：研究了熔体过热处理对Al-11%Si合金形核温度、结晶潜热和凝固组织的影响规律.实验结果发现合金的形核温度先随过热温度的升高而降低;过热温度超过860℃后,过热温度对形核温度没有明显影响.合金的结晶潜热随过热温度的升高具有先减小后增大的规律,过热温度为860℃时,结晶潜热达到其最小值.过热温度过低和过高时,共晶硅均为粗大的针片状,表现出小平面生长的特征;过热温度为860℃时,共晶硅为细小的点状,表现出非小平面生长的一些特征.The effect of melt superheating on the nucleation temperature, the latent heat ot crystallization and the solidification structure of Al-11 %Si alloy have been studied experimentally. The experimental results show that the nucleation temperature firstly decreases with increasing the superheating temperature, and then does not vary with the superheating temperature when the temperature is beyond 860 ℃. The latent heat of crystallization firstly decreases and then increases with increasing the superheating temperature, and reaches its minimum when the temperature is 860 ℃. When the temperature is 860 ℃, the eutectic silicon is in short rod or small point form, which shows some feature of non-lateral growth. When the superheating temperature is too high or too low, the eutectic silicon is in large plate form, which shows the feature of lateral growth.

关 键 词：Al—Si合金 熔体过热 形核温度 结晶潜热 凝固组织 

分 类 号：TG131[一般工业技术—材料科学与工程]