T2紫铜搅拌摩擦焊工艺

Friction stir welding process of T2 copper

对5 mm厚T2紫铜开展了搅拌摩擦焊工艺的研究,分析了焊接工艺参数对焊缝表面成形、接头宏观形貌、显微组织及力学性能的影响。结果表明,在较宽的焊接工艺参数范围内均可得到无内部缺陷的接头。接头宏观形貌由焊核区、热机影响区、热影响区和母材组成。随着搅拌头旋转速度的增加或焊接速度的降低,碗形的接头的宏观形貌轮廓逐渐模糊,焊核区的晶粒逐渐粗化,接头的抗拉强度逐渐降低。当焊接工艺参数为400 r/min,200 mm/min时,接头的抗拉强度最高,达到母材的95.9%,S线对接头拉伸性能无影响。热影响区的显微硬度值最低,与接头的断裂位置一致。

Friction stir welding process of 5 mm T2 copper was studied.Influence of welding parameters on surface formation of welds,macroscopic appearance of joints,microstructures and mechanical properties were analyzed.The results showed that welded joints without internal defects could be obtained within a wide range of welding parameters.Macroscopic appearance showed that joints consisted of nugget zone,thermo-mechanically affected zone,heat affected zone and parent metal.With increase of rotation speed of the stirring head or decrease of welding speed,bowl-shaped macroscopic appearance of joints got blurred,grains of nugget zone became roughened,and tensile strength of joints was gradually reduced.When welding parameters were 400 r/min,200 mm/min,tensile strength of joints was the highest,reaching 95.9%of base metal,and S line had no effect on tensile properties of joints.The lowest microhardness occurred in heat affect zone,which was in line with fracture positions of joints.