铝锂合金的焊缝组织与开裂敏感性研究  

Microstructure and Crack Susceptibility of Aluminium-Lithium Alloy Weldment

作　　者：李小飞[1] 李晓红[1] 熊华平[1] 李艳[1] 郭绍庆[1] 张学军[1] 

机构地区：[1]北京航空材料研究院,北京100095

出　　处：《航空材料学报》2007年第3期55-59,共5页Journal of Aeronautical Materials

摘　　要：采用横向变拘束试验,研究铝锂合金(A合金)和2024合金的焊接热裂纹敏感性;并对焊缝组织进行分析,探讨它对两种合金焊接开裂倾向的影响。结果表明,A合金焊缝组织为柱状枝晶,在焊缝与热影响区之间由于非均匀形核而形成精细等轴晶粒区域(EQZ),而2024合金焊缝为联生结晶的胞状枝晶组织。两种合金焊缝组织的差异造成A合金有更高的焊接热裂纹敏感性。By using the transvarestraint test,the welding hot cracking susceptibility of aluminium-lithium（Al-Li） alloy and 2024 alloy has been estimated. The microstructure of the tested alloys were systemically investigated by means of optical microscope and JSM - 5600 scanning electron microscope（ SEM ）, and the relation between microstructure and the welding hot cracking susceptibility was discussed. The results have shown that the microstructure of A alloy in welding metal was columnar dendritic, and, due to heterogeneous nucleation mechanism, there was fine equiaxed grains region （EQZ） adjacent to the fusion boundary. By contrast, the microstructure of 2024 alloy was cellular dendritic due to epitaxial growth mechanism. The different microstructure caused higher welding hot cracking susceptibility of A alloy.

关 键 词：铝锂合金 焊缝组织 焊接热裂纹 

分 类 号：TG406[金属学及工艺—焊接]