2A12与3A21铝合金搅拌摩擦焊微观组织分析

Analysis on Microstructure of Friction-Stir Welding for 2A12 and 3A21

主要研究了2A12铝合金与3A21铝合金对接的搅拌摩擦焊工艺,并对焊后试样进行了金相观察。结果表明,焊核区为近球形的晶粒,与母材相比焊核区晶粒细小、分布均匀。在热循环作用下,返回侧2A12铝合金热影响区、热机影响区晶粒与前进侧3A21铝合金相比明显长大。在焊缝前进侧热影响区与母材存在明显的界线。

2A12 and 3A21 aluminum friction stir welding process was mainly studied and the metallograph of welding was observed. The metallograph show that nugget zone is nearly spherical grains. The grain size of weld nugget zone is fine and homogeneous distribution compared with the base metal. Under welding thermal cycle, the grain size of heat affected zone and the thermo-mechanically affected zone of retreating side significantly increases compared with the advanced side. The boundary is observed between heat affected zone and base metal in forward side of the weld seam.