提高7050铝合金形核率的试验及理论分析  

Experimental and Theoretical Analysis on Enhancing Nucleation Rate of 7050 Aluminum Alloy

作　　者：胡谦谦[1] 张立华[1] 

机构地区：[1]中南大学机电工程学院,高性能复杂制造国家重点实验室,湖南长沙410083

出　　处：《铸造》2011年第12期1175-1179,1184,共6页Foundry

基　　金：国家“973”项目“航空航天用高性能轻合金大型复杂结构件制造的基础研究”(2010CB731700)

摘　　要：结合大铸锭的超声铸造试验和理论研究,从结晶热力学和动力学两方面定量分析了不同功率的超声引起的7050铝合金凝固过程中形核率的变化。研究发现,导入超声外场后,晶核形核率显著增大,而且形核率随超声功率的增大而增大。超声铸造与普通铸造相比,形核率提高了106到108倍。研究表明,熔体温度及过冷度是控制形核率变化的主要变量,并推导出了7050铝合金铸造过程中的形核率与温度和过冷度之间的数学模型。The change of nucleation rate, caused by different power of ultrasound, during the solidification process of 7050 aluminum alloy has been analyzed quantitatively from both thermodynamics and kinetics of crystallization. The research indicates that nucleation rate increases significantly with the acting of ultrasound and it gets higher with the increase of the ultrasonic power. In the process of ultrasound casting, the nucleation rate increases by 108 to 108 times when compared with that of conventional casting. The temperature of the aluminum alloy melt and the undercooling degree are the main variables which can influence the change of the nucleation rate. The mathematical model among the nucleation rate of 7050 aluminum alloy, undercooling degree and melt temperature were derived.

关 键 词：7050铝合金 超声铸造 形核率 理论研究 

分 类 号：TG292[金属学及工艺—铸造]