AZ91D镁合金搅拌摩擦焊接头组织与性能  

Microstructure and Properties of Friction Stir Weld Joints of Cast Magnesium Alloy AZ91D

作　　者：刘畅[1,2] 戚文军[2] 邓运来[1] 周楠[2] 李林[2] 

机构地区：[1]中南大学材料科学与工程学院,湖南长沙410083 [2]广东省工业技术研究院(广州有色金属研究院)材料加工研究所,广东广州510650

出　　处：《铸造技术》2011年第11期1546-1549,共4页Foundry Technology

基　　金：广东省科技计划项目(2008A090300004);广州有色金属研究院科技项目(2010B009)

摘　　要：采用搅拌摩擦焊对AZ91D镁合金进行焊接试验,研究了搅拌摩擦焊接头的组织与性能。结果表明,当转速为1 000～1 400r/min、焊速为50～150mm/min时,均可得到表面成形良好、内部无孔洞和隧道的焊缝;焊接区与母材组织差异极大,焊接区形成细小、均匀的再结晶组织,具有锻造组织特征;热影响区为部分再结晶组织,再结晶晶粒沿原铸造晶粒的晶界生长;对接头进行拉伸试验,断裂发生在母材处,表明接头的抗拉强度高于母材。The welding experiment on as-cast AZ91D magnesium alloy was performed by friction stir welding （FSW）. The microstructure and properties of the welded joint were investigated. The results show that, when the rotation speed of the stir head is between 1 000 r/min and 1 400 r/min, the welding speed is in the range of 50 mm/min to 150 mm/min, the welding zone with excellent surface quarity and no internal holes and tunnels can be got. The microstructure of the welded regions is quite different from the base metal. The crystal grains become small and uniform at the J typical friction stir weld joint zone, and the microstructure is a kind of wrought structure. Within heat affected zone （HAZ）, there are partial re-crystallized grains. These re-crystallized grains forms along with original casting grains boundary. Because transverse tensile test of FSW joint results in the fracture from base metal, the tensile strength of FSW joint is much higher than that of base metal.

关 键 词：AZ91D镁合金 搅拌摩擦焊 微观组织 力学性能 

分 类 号：TG407[金属学及工艺—焊接]