摘要
LY12CZ(A2024-JIS)铝合金板材点焊熔核的凝固组织是由柱状组织和等轴组织共同组成。本文利用光镜和扫描电镜不仅反映了熔核的“柱状+等轴”组织形貌,而且直观、精细地揭示出其组成单元——粗大柱状晶和粗大等轴晶(本文命名)的内部结构及形态特征,并从结晶机理上作了分析,进一步提出了点焊熔核“柱状+等轴”组织形成过程模型。
The solidified structure of nuggets in Ly12CZ(A2024-JIS)alloy is co- mposed of columnar and equiaxial grains.This paper reveals not only the mo- rphology of the solidified structure but also the internal structute and the co- nfigurational feature of coarste columnar grains and coarse equiaxed grains in Ly12CZ alloy by means of a microscope and an SEM.On the basis of analysing the crystallinic mechanism,a model is presented here which shows the forming process of coarse columnar and equiaxed grains in a nugget.
关键词
点焊
熔核
凝固组织
铝合金
Spot welding nugget
solidification process
