超声处理铝合金熔体对半连铸大铸锭组织与偏析的影响  

Effect of Aluminum Alloy Melt Treated with Ultrasound on Microstructure and Segregation of Large-scale Ingot in Semi-continuous Casting

作　　者：郭兴[1,2] 蒋日鹏[1,2] 李晓谦[1,2] 李瑞卿[1,2] 彭搏涛 

机构地区：[1]中南大学机电工程学院,湖南长沙410083 [2]高性能复杂制造国家重点实验室,湖南长沙410083

出　　处：《热加工工艺》2016年第7期25-29,共5页Hot Working Technology

基　　金：国家自然科学基金面上项目(CX2011B090);国家973计划资助项目(2012CB619504)

摘　　要：在Ф1250 mm规格2219铝合金铸锭半连铸过程中,对结晶器中的熔体施加恒定功率的超声波处理,研究了超声处理熔体对大规格铸锭成分偏析的影响规律与作用机制。结果表明,在非对称超声场的作用下,铸锭整个断面的凝固组织均获得显著细化,晶粒尺寸减小且分布趋于均匀,溶质元素Cu的宏观偏析与显微偏析均得到了显著改善,与未加超声处理的铸锭试样相比,晶内相对固溶程度提高了13%,Cu元素的宏观偏析指数降低了24%。分析认为,超声的细晶作用以及超声声流、空化脉冲波促进的溶质元素扩撒对改善偏析具有积极影响。By applying a constant ultrasound power to process the melt in the mould during semi-continuous casting of aluminum alloy 2219 ingot with size of φ1250 mm, the effects of ultrasonic treatment on the rule and function mechanism of composition segregation of large-scale ingot were researched. The results show that the microstructure of the whole section is refined obviously under the asymmetry ultrasonic field. The grain size decreases and tends to be more evenly distributed. Moreover, the micro-segregation and macro-segregation of Cu element are both improved significantly. Compared with the samples without ultrasonic treatment, the relative solid solubility of Cu improves by 13% and its macro-segregation index decreases by 24%. The grain refinement of ultrasound treatment, ultrasonic stream and solute element diffusing promoted by cavitation pulse wave play a positive role in improving the segregation.

关 键 词：铝合金 超声处理 半连铸 晶粒细化 偏析 

分 类 号：TB559[理学—物理] TG249.9[理学—声学]