磁场强度对半连铸铝合金液穴形状及凝固组织的影响  

EFFECTS OF ELECTROMAGNETIC INTENSITY ON THE SUMP SHAPES AND STRUCTURES OF ALUMINUM ALLOY PRODUCED BY CREM PROCESS

作　　者：张勤 崔建忠[1] 路贵民[1] 张北江[1] 

机构地区：[1]东北大学材料电磁过程教育部重点实验室,沈阳110006

出　　处：《金属学报》2002年第9期956-960,共5页Acta Metallurgica Sinica

基　　金：国家重点基础研究发展规划资助项目 G199906490501

摘　　要：对不同强度低频交变电磁场作用下,CREM法半连铸7075铝合金过程中液穴形状、表面质量及微观组织的变化规律进行了实验研究,并对电磁场作用下,合金铸锭裂纹的消除机制进行了理论分析.结果表明:随着磁场强度增大,弯液面曲率半径及熔体与结晶器接触高度减小,初凝壳形成位置点降低,液穴深度变浅,铸锭表面质量提高,铸锭中近球形组织增加,蔷薇形组织减少,整体组织变得更加细小和均匀,开裂现象得到消除.Under the effect of electromagnetic field with low frequency, the evolutions of sump shape, surface quality and microstructures of as-cast 7075 alloy ingot produced by CREM process with electromagnetic intensity have been experimentally investigated. Meanwhile, the mechanism of eliminating hot tear is discussed. The results show that with the enhancement of electromagnetic intensity, the curvature of surface meniscus and the height of contact line between melt and mold decrease, the forming position of primary solidified shell becomes lower and sump height becomes more shallow, which improve the quality of surface, make microstructure finer and more uniform and eliminate the phenomenon of hot tear.

关 键 词：磁场强度 CREM法 7075铝合金 液穴形状 微观组织 热裂 半连续铸造 

分 类 号：TG146.21[一般工业技术—材料科学与工程] TG249.7[金属学及工艺—金属材料]