受控扩散凝固结合复合变质对高硅铝合金组织和性能的影响  

Effect of CDS Combined with Complex Modification on Microstructure and Properties of High-silicon Aluminum Alloy

作　　者：吕勋 余水金 余智成 汪天培 王奎 蒋海燕[1] LYU Xun;YU Shuijin;YU Zhicheng;WANG Tianpei;WANG Kui;JIANG Haiyan(School of Material Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China;Fujian Taida High- tech Material Co., Ltd., Sanming Fujian 353399,China)

机构地区：[1]上海交通大学材料科学与工程学院,上海200240 [2]福建泰达高新材料有限公司,福建三明353399

出　　处：《上海金属》2020年第4期72-77,共6页Shanghai Metals

基　　金：国家自然科学基金(No.51804197)。

摘　　要：采用受控扩散凝固(CDS)技术结合复合变质剂制备了Al-30%Si(质量分数)合金,研究了CDS和复合变质的机制,及其对合金组织的演变和力学性能的影响。结果表明:由于过冷产生的大量晶核和引发的强制对流,CDS技术可以有效地细化初晶硅。通过在高温熔体中添加含P变质剂,在低温熔体中添加含Sr变质剂,解决了普通铸造中P与Sr不能同时添加的问题,使初晶硅尺寸由原来的超过250μm细化到了24.7μm,共晶硅也由针片状变质为颗粒状。合金的抗拉强度从24.6 MPa提高到了136.76 MPa、断后伸长率从几乎为零增加到了0.82%。Al-30%Si(by mass)alloy was prepared by controlled diffusion solidification(CDS)combined with complex modifier.The mechanisms of CDS and complex modification,and their effects on the microstructure evolution and mechanical properties of the alloy were studied.The results showed that CDS could effectively refine primary silicon because of a large number of nuclei caused by supercooling and forced convection.By adding P-containing modifier to high temperature melt and Sr-containing modifier to low temperature melt,the problem that P and Sr cannot be simultaneously added to traditional casting was solved.As a result,the size of primary silicon was refined from over 250μm to 24.7μm,and the eutectic silicon was also changed from acicular to granular.The tensile strength of the alloy increased from 24.6 MPa to 136.76 MPa,and the elongation increased from almost 0 to 0.82%.

关 键 词：受控扩散凝固(CDS) 复合变质 高硅铝合金 

分 类 号：TG1[金属学及工艺—金属学]