冷却条件对2519A铝合金搅拌摩擦焊焊缝性能的影响
来源期刊：中南大学学报(自然科学版)2012年第10期
论文作者：宋继超 叶凌英 张新明 贺地求 李红萍
文章页码：3801 - 3806
关键词：搅拌摩擦焊；2519A铝合金；焊接冷却工艺；硬度；析出相；强度
Key words：friction stir welding; 2519A aluminum alloy; welding cooling conditions; hardness; precipitates; strength
摘 要：采用搅拌摩擦焊焊接厚度为2.75 mm的2519A铝合金板材。分别研究在空气和水流中冷却对焊接性能和焊缝组织的影响。实验结果表明：在旋转速度为2 700 r/min，焊接速度为60 mm/min条件下，水冷焊接得到美观并无明显缺陷的接头，提高了接头强度，抗拉强度达到340 MPa；在水冷条件下，热影响区的范围变窄，热影响区平均硬度提高，焊核区晶粒粒度比空冷条件下的更加小，硬度几乎呈直线分布；而在空冷条件下，焊核区硬度呈先上升后下降趋势，变化明显，水冷焊核区平均硬度低于空冷条件下平均硬度，这是因为空冷焊接能够提高固溶度并促进随后的时效发生。
Abstract: Friction stir welding was used to weld 2.75 mm thick 2519A aluminum sheets. The sheets were welded in conventional condition (in air) and flowing water condition. The influence of cooling conditions on the microstructure and mechanical properties of the joint was investigated. The results indicate that with the rotation speed of 2 700 r/min and welding speed of 60 mm/min, the water cooling welding results in better joint, and improves the joint strength to 340 MPa. In water cooling condition, the softening region becomes remarkably narrow, and its hardness value is improved. Moreover, the grain size of the nugget zone is much smaller than the grain size in air cooling condition. In water cooling, the distribution of the hardness in the nugget zone is almost a straight line, while in air cooling, the hardness in nugget zone firstly becomes higher and then lower, and it changes significantly. The average hardness in the nugget zone by water cooling is smaller than the average hardness in air cooling condition, because the air cooling can improve the solution degrees and promote the aging process.
宋继超1，叶凌英1，张新明1，贺地求2，李红萍3
(1. 中南大学 材料科学与工程学院，湖南 长沙，410083；
2. 中南大学 机电工程学院，湖南 长沙，410083；
3. 中国商飞上海飞机设计研究院，上海，200232)
摘 要：采用搅拌摩擦焊焊接厚度为2.75 mm的2519A铝合金板材。分别研究在空气和水流中冷却对焊接性能和焊缝组织的影响。实验结果表明：在旋转速度为2 700 r/min，焊接速度为60 mm/min条件下，水冷焊接得到美观并无明显缺陷的接头，提高了接头强度，抗拉强度达到340 MPa；在水冷条件下，热影响区的范围变窄，热影响区平均硬度提高，焊核区晶粒粒度比空冷条件下的更加小，硬度几乎呈直线分布；而在空冷条件下，焊核区硬度呈先上升后下降趋势，变化明显，水冷焊核区平均硬度低于空冷条件下平均硬度，这是因为空冷焊接能够提高固溶度并促进随后的时效发生。
关键词：搅拌摩擦焊；2519A铝合金；焊接冷却工艺；硬度；析出相；强度
SONG Ji-chao1, YE Ling-ying1, ZHANG Xin-ming1, HE Di-qiu2, LI Hong-ping3
(1. School of Materials Science and Engineering, Central South University, Changsha 410083, China;
2. School of Mechanical and Electrical Engineering, Central South University, Changsha 410083, China;
3. Shanghai Aircraft Design and Research Institute of COMAC, Shanghai 200232, China)
Abstract:Friction stir welding was used to weld 2.75 mm thick 2519A aluminum sheets. The sheets were welded in conventional condition (in air) and flowing water condition. The influence of cooling conditions on the microstructure and mechanical properties of the joint was investigated. The results indicate that with the rotation speed of 2 700 r/min and welding speed of 60 mm/min, the water cooling welding results in better joint, and improves the joint strength to 340 MPa. In water cooling condition, the softening region becomes remarkably narrow, and its hardness value is improved. Moreover, the grain size of the nugget zone is much smaller than the grain size in air cooling condition. In water cooling, the distribution of the hardness in the nugget zone is almost a straight line, while in air cooling, the hardness in nugget zone firstly becomes higher and then lower, and it changes significantly. The average hardness in the nugget zone by water cooling is smaller than the average hardness in air cooling condition, because the air cooling can improve the solution degrees and promote the aging process.
Key words:friction stir welding; 2519A aluminum alloy; welding cooling conditions; hardness; precipitates; strength
