Al-La合金不连续枝晶组织形成机理  

Formation mechanism of the discontinuous dendrite structure in Al-La alloys

作　　者：郑亚虹[1,2] 王自东[1] 董晓娟[1] 

机构地区：[1]北京科技大学材料科学与工程学院,北京100083 [2]无锡市广播电视大学,无锡214011

出　　处：《北京科技大学学报》2009年第9期1132-1137,共6页Journal of University of Science and Technology Beijing

基　　金：国家重点基础研究发展计划资助项目(No.2006CB605200)

摘　　要：在Al-La合金的自由凝固试样中,发现Al-35%La合金组织形貌的特殊性,其先结晶相Al11La3枝晶沿主干方向成分是不连续的.为验证这种组织存在的真实性,采用定向凝固方法制备了不同冷却速度下的Al-35%La合金试样,结果显示出定向凝固Al-35%La合金中Al11La3枝晶沿主干方向成分是不连续的.在此基础上,分析了化学成分与凝固速度对Al-La合金组织的影响,并初步探讨了这种不连续枝晶的形成机理.Al-La alloy samples with different compositions were prepared by a free solidification method. The results show that the dendrite structure of Al11La3 in an Al-35 % La alloy is discontinuous. For demonstrating the authenticity of this structure, adopting a directional solidification method, Al-35 % La alloy samples were prepared at different solidification rates. It is indicated that the dendrite structure of Al11La3 in the Al-35 % La alloy obtained by directional solidification is discontinuous. The effects of composition and solidification rate on the microstructure of Al-La alloys were analyzed, and the formation mechanism of the discontinuous dendrite structure was discussed preliminarily.

关 键 词：二元合金 铝 镧 凝固 定向凝固 枝晶组织 

分 类 号：TG146.21[一般工业技术—材料科学与工程]