1.2熔池的凝固过程-焊缝横断面结晶模式 centerline equlaxed fusion zone welding dendritic direction weld columnar dendritic pool dendritic pool boundary cellular ccllular planar planar fusion base line <100> <100> <100> metal 50μm base metal Variation in solidification mode Planar-to-cellular and cellular-to- across the fusion zone dendritic transitions in 1100 Al welded with 4047 fillerVariation in solidification mode across the fusion zone Planar-to-cellular and cellular-to￾dendritic transitions in 1100 Al welded with 4047 filler 1. 2 熔池的凝固过程-焊缝横断面结晶模式