镁合金薄板的搅拌摩擦焊工艺

搅拌摩擦焊是一种新型的塑化连接工艺，对于用熔化焊方法难于焊接的有色金属，有着极大的应用潜力。本文针对我国航空航天工业中常用的MB8镁合金，试验研究了镁合金薄板的搅拌摩擦焊工艺，对焊缝的成形特点、接头组织特征及力学性能进行了分析探讨。结果表明，MB8镁合金塑化连接的接头外观成形良好，内部无气孔、裂纹，焊后焊件几乎无变形，接头性能可达到母材抗拉强度的76％。塑化连接接头由焊核和热影响区组成，焊核区是经历了动态再结晶的细小晶粒，热影响区的晶粒较粗大。

Friction stir Welding of MB8 Magnesium Alloy Sheet

Friction Stir Welding (FSW) is a new plasticized joining process which has considerable potential for welding non ferrous alloys,which are often difficult to be weld by fusion welding.In this paper,the FSW process for Magnesium alloy,which is very useful for aviation and aerospace industry,was studied and the basic characterization of the weld formation,the structures and the mechanical properties of the joint were discussed.The experimental results shown that the excellent external appearance and the low distortion of the plastic joint for MB8 Magnesium alloy have been obtained by using of FSW and there is no porosity and cracking in the joint.The high joint strength was achieved.The weld zone is comprised of the weld nugget with the fine equiaxed grains and the heat affected zone (HAZ) with the coarsened grains.