LF21铝合金厚板搅拌摩擦焊接接头微观组织研究  

Microstructure in friction stir welding of thick LF21 aluminum alloy

作　　者：赵勇[1] 卢学府 付娟[1] 方圆[1] 严铿[1] 

机构地区：[1]江苏科技大学先进焊接技术省级重点实验室,江苏镇江212003 [2]广州中船黄埔造船有限公司,广东广州510715

出　　处：《江苏科技大学学报（自然科学版）》2009年第2期117-120,共4页Journal of Jiangsu University of Science and Technology:Natural Science Edition

摘　　要：针对14 mm厚的LF21铝合金,采用搅拌摩擦焊进行焊接,焊后对接头的宏观形貌、微观组织和接头不同区域的显微硬度进行分析.实验结果表明:在焊接速度v为200 mm.min-1,转速ω为1 200 rad.min-1时,焊缝成型较美观,焊缝内部无空洞、裂纹等缺陷.显微组织观察发现焊核区的组织为再结晶等轴晶粒,晶粒明显细化;热机械影响区组织由原始母材细纤维组织转变为具有一定弧度的弯曲粗纤维组织;热影响区范围较窄,晶粒与母材相似,但出现了晶粒粗化现象.显微硬度实验发现,焊缝中层和上层的显微硬度较高,而下层较低.In this paper, 14 mm thick LF21 rust-resisting aluminum alloy was jointed by friction stir welding, and its macro-organization and microstructure were analyzed. Experiment shows that weld can be divided into weld heat affected zone, thermal mechanical affected zone, and weld nugget regions. Among them, weld nuggets obviously are recrystallized isometric grains, and grains are obvious refining. There are many coarse grains in thermal mechanical affected zone from a small base metal deformation of fibrous tissue to radian bending coarse fibrous tissue. Furthermore, the microstructure of heat affected zone and base metal are similar. However, there is a coarsening phenomenon. In micro hardness testing, the middle and upper micro hardness of the welded joint are relatively high, while the lower micro hardness is significant.

关 键 词：LF21铝合金 搅拌摩擦焊 微观组织 显微硬度 

分 类 号：TG457.14[金属学及工艺—焊接]