超声铸造7050铝合金的微观组织和宏观偏析规律  

Microstructure and macro-segregation law of ultrasonic cast 7050 aluminum alloy ingots

作　　者：陈鼎欣[1] 李晓谦[1] 黎正华[1] 蒋日鹏[1] 

机构地区：[1]中南大学机电工程学院现代复杂装备设计与极端制造教育部重点实验室,长沙410012

出　　处：《北京科技大学学报》2012年第6期666-670,共5页Journal of University of Science and Technology Beijing

基　　金：国家重点基础研究发展规划资助项目(2010CB731706)

摘　　要：采用不同功率超声对铝熔体进行处理,研究超声场对7050铝合金凝固组织和宏观偏析的影响规律.结果表明:超声振动产生的空化效应和声流效应影响熔体的凝固过程,合理功率的超声能有效细化晶粒、优化组织及改善宏观溶质分布.当超声功率达到170 W时,铸锭径向宏观偏析的弱化效果最好,Zn、Mg和Cu的偏析指数分别为0.0593、0.0565和0.0319;超声功率超过170 W,溶质元素在中心区域富集量显著提高,宏观偏析程度增大.Ultrasonic vibration effects on the microstructure and macro-segregation of 7050 aluminum alloy were investigated by adopting various ultrasonic powers to the aluminum meh. It is found that cavitation effect and acoustic streaming effect, caused by ul- trasonic vibration, play a major role in the solidification process. A reasonable ultrasonic power can obviously refine the grains, opti- mize the microstructure, and improve the homogeneity of solute elements. The maximum decrease of the macro-segregation level occurs at the power of 170 W, and the segregation index values of Zn, Mg, and Cu are 0. 059 3, 0. 056 5, and 0.031 9, respectively. Exceeding the power of 170 W, the rich level of solute elements in the ingot center enhances greatly and the macro-segregation level increases.

关 键 词：铝合金 铸造 超声应用 偏析 微观组织 空化 声流 

分 类 号：TG249.7[金属学及工艺—铸造] TG146.2[一般工业技术—材料科学与工程]