(南昌航空大学 航空制造与工程学院，南昌 330063)
摘 要: 采用对接方式对2 mm厚的T2紫铜板和2 mm厚的2A16铝合金板进行真空电子束焊。通过力学拉伸研究焊接速度、电子束流、扫描幅值对接头力学性能的影响，通过电镜扫描观察接头的显微组织形貌。结果表明:接头抗拉强度随着焊接速度、电子束流、扫描幅值的增大均呈先增大后减小的趋势;当焊接速度为1800 mm/min，电子束流为62 mA，扫描幅值为0.8 mm时抗拉强度达到最大值71 MPa。电子束流固有的冲击搅拌作用和其O型扫描作用对熔池中心组织有细化作用，会促进等轴块状相的生成，抑制组织的棒状生长。在熔池中心，各相的分布均匀，白色的网状化合物Al2Cu相遍布熔池中，暗灰色的Al相呈等轴块状被包裹在网状相的内部;靠铝侧热影响区相呈短棒状，紧靠铜侧的化合物层为Al2Cu层。
关键字: 紫铜;铝合金;电子束焊;力学性能;显微组织
（College of Aviation Manufacturing and Engineering, Nanchang Hang Kong Uiniversity, Nanchang 330063, China）
Abstract:2.0 mm-thick T2 copper and 2.0 mm-thick 2A16 aluminum were welded by vacuum electron beam welding machine. The effects of welding velocity, electron beam and scanning magnitude on the mechanical properties were studied through the mechanical tensile. The microstructure of the joint was studied by SEM. The results show that, the tensile strength of joint increases firstly then decreases with increasing the welding speed, electron beam and the magnitude of scanning. When the welding speed is 1800 mm/min, the electron beam current is 62 mA, the magnitude of scanning is 0.8 mm, the tensile strength reaches the maximum of 71 MPa. The stirring action and O-scan of electron beam refine the microstructure of molten pool and promote the appearance of equiaxial massive phase. Each phase distributes uniformly in the pool. White Al2Cu compounds are reticular in the center of molten pool. The dark gray Al phase is wrapped by Cu-Al compounds and presented equiaxed block. Phase near the HAZ of aluminum side is short rod. The compound layer close to the side of the copper is Al2Cu layer.
Key words: copper; aluminum; electron beam welding; mechanical property; microstructure
