摘要
８０９０铝锂合金焊缝中存在一种细小的等轴光滑晶，其形态和形成机制与等轴树枝晶不同。细等轴晶沿凝固停顿线生长，主要在熔合线附近形成，在焊缝内部呈带状分布。研究表明细等轴晶的形成要求特殊的化学成分（含Ｚｒ，Ｌｉ元素）和一定的凝固条件（小的成分过冷度）。在细晶区由于晶界含较多的第二相，导致穿过该区的破坏呈现沿晶特征。
A kind of fine equiaxed smooth grains,which is different from equiaxed dendrites in both morphology and formation mechamism,was observed in 8090 Al-Li alloy welds.The fine equiaxed smooth grains mainly existed near the fusion boundaries and grew into a band along the solidification-pause lines in the welds.It was found that the existence of a particular solidification condition(i.e. smaller constitutional undercooling degree)as well as the elements of zirconium and lithium was necessary for the fine equiaxed smooth grains to form. Fractures which pass through the fine grain zone are predominately intergranular,since there is a larger amount of second phase along the grain boundaries of this zone.
出处
《焊接学报》
EI
CAS
CSCD
北大核心
1996年第1期1-6,共6页
Transactions of The China Welding Institution
基金
国家自然科学基金
关键词
铝锂合金
焊缝
凝固组织
s:aluminum-lithium alloy weld,equiaxed smooth grain, equiaxed dendrite,constitutional undercooling,intergranular fracture
