熔体温度处理和合金成分对铝硅合金凝固收缩率的影响  

Effect of the Melt Temperature Treatment and Alloy Composition on the Solidification Shrinkage of Al-Si Alloy

作　　者：坚增运[1] 党博[1] 常芳娥[1] 许军锋[1] 文强[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》2014年第2期124-130,共7页Journal of Xi’an Technological University

基　　金：国家自然科学基金项目(51171136)

摘　　要：合金凝固过程的收缩会使铸件产生缩孔、缩松、热裂、应力和冷裂等缺陷.运用阿基米德原理设计了测定合金凝固收缩率的实验装置,并研究了Al-25%Si合金凝固收缩率随熔体温度处理和合金化元素的变化规律.试验结果发现:Al-25%Si合金凝固收缩率随过热温度的升高先减小后增大,随降温后保温时间的延长,收缩率逐渐减小;当熔体在960℃保温30min后,又在770℃保温60min时,凝固收缩率达到最小值0.40%.单独加入Cu、Ni和Mn元素时,凝固收缩率分别从0.87%逐渐减小到0.77%、0.75%和0.52%.但是单独加入Mg元素时,凝固收缩率从0.87%逐渐增加到0.92%.Alloy solidification shrinkage can cause defects such as shrinkage hole ,shrinkage porosity , hot cracking and cold cracking .The experimental device for measuring the alloy solidification shrinkage using Archimedes＆#39;principle is designed and the effects of melt temperature treatment and alloying elements on the solidification shrinkage of Al-25% Si alloy are investigated .It is found that the solidification shrinkage of Al-25% Si alloy decreases first and then increases with increasing superheating-temperature ,and it decreases with increasing holding-time gradually .When the melt is hold at 960 ℃ for 30min and then at 770 ℃ for 60min ,the shrinkage reaches the minimum 0 .40% .With increasing the content of the copper ,nickel and manganese ,the solidification shrinkage decreases from 0 .87% to 0 .77% ,0 .75% and 0 .52% respectively ,but with increasing the content of the magnesium it increases from 0 .87% to 0 .92% .

关 键 词：AL-SI合金 凝固收缩率 熔体温度处理 合金化元素 

分 类 号：TG292[金属学及工艺—铸造]