Sr添加量对过共晶Al-20%Si合金铸态组织和硬度的影响  

Effect of Sr Additive Amount on Cast Structure and Hardness of Hypereutectic Al-20%Si Alloy

作　　者：孙雪 石为喜[1] 张译文 李祉澈 王浩宇 SUN Xue;SHI Weixi;ZHANG Yiwen;LI Zhiche;WANG Haoyu(School of Metallurgy and Materials Engineering,Liaoning Institute of Science and Technology,Benxi Liaoning,117004,China)

机构地区：[1]辽宁科技学院冶金与材料工程学院,辽宁本溪117004

出　　处：《辽宁科技学院学报》2024年第5期9-12,共4页Journal of Liaoning Institute of Science and Technology

基　　金：2025年辽宁科技学院大学生创新创业训练计划项目(202511430022);辽宁省教育厅基本科研项目(面上项目)(LJKZ1066,2023J0918)。

摘　　要：采用Al-10%Sr对Al-20%Si合金进行变质处理,研究Sr对Al-20%Si合金的铸态组织和硬度的影响。Sr可以同时细化Al-20%Si合金中的初晶硅和共晶硅,当Sr的添加量达到0.4%时,初晶硅晶粒细化效果最明显,初晶硅的形貌由大的板块状变为变态后的细的鱼骨状,共晶硅由长针状变为颗粒状。X射线衍射分析表明,在变质后的合金中生成了Al_(2)Si_(2)Sr相。扫描电镜分析表明,当Sr添加量为0.4%时,Al-20%Si合金样品中出现了白色的菱形组织Al_(2)Si_(2)Sr相,即XRD测试分析中的Al-Si-Sr三元相。硬度试验表明,当Sr的添加量为0.4%时,Al-20%Si合金的硬度达到最大值64 HB,随着Sr添加量的进一步增加,其硬度呈现下降趋势。Al-10%Sr was adopted as modifier to refine Al-20%Si alloy in this paper,and the effect of different additive amount of Sr on the cast structure and properties of Al-20%Si alloy was investigated.The results showed that Sr can simultaneously refine both primary and eutectic silicon in Al-20%Si alloy.When the addition of Sr reaches 0.4%,the grain size of primary silicon is obviously refined.The morphology of primary silicon changes from large plate to fine fishbone,and eutectic silicon changes from long needle to dot.X-ray diffraction(XRD)analysis indicated the formation of Al_(2)Si_(2)Sr phase in the modified alloy.Scanning electron microscopy analysis showed that when the Sr addition amount is 0.4%,white diamond shaped Al_(2)Si_(2)Sr phase appears in the Al-20%Si alloy sample,which is the Al-Si-Sr ternary phase revealed by XRD analysis.The results of hardness test showed that the hardness of Al-20%Si alloy reaches the maximum value of 64 HB when the addition of Sr is 0.4%.With the further increase of Sr addition,the hardness of Al-20%Si alloy shows a downward trend.

关 键 词：过共晶铝硅合金 SR变质 初晶硅 硬度 

分 类 号：TG146.2[一般工业技术—材料科学与工程] TG113[金属学及工艺—金属材料]