ZL114A/5A06铝合金电子束焊接头组织与性能

Microstructure and Mechanical Properties of Electron Beam Welded Joints of ZL114A/5A06 Aluminum Alloy

摘要: 采用真空电子束焊接工艺对ZL114A和5A06铝合金板进行焊接，利用金相显微镜和扫描电镜对焊接接头的微观组织进行了分析，并测试了接头的显微硬度分布和拉伸性能。最后，借助扫描电镜对拉伸断口形貌进行了观察。结果表明，ZL114A/5A06电子束焊接头成形良好，焊缝区由细小的等轴晶和树枝晶组成，其晶粒尺寸显著小于两侧母材；接头显微硬度由两侧向焊缝中心急剧攀升，焊缝中心达到最高值；焊接接头抗拉强度略低于ZL114A母材，失效方式为低塑性断裂，断口上存在大量平整的解理面、解离台阶和微裂纹。

Abstract: Vacuum electron beam welding was employed to join ZL114A and 5A06 aluminum alloy plates. The microstructure of the welded joint was analyzed using metallographic microscopy and scanning electron microscopy, while the microhardness distribution and tensile properties of the joint were also evaluated. Additionally, the fracture morphology of the tensile specimens was examined by scanning electron microscopy. The results indicate that the ZL114A/5A06 electron beam welded joint are well formed, with the weld zone consisting of fine equiaxed crystals and dendritic structures, whose grain size is significantly smaller than that of the base materials on both sides. The microhardness of the joint increases sharply from both sides toward the weld center, reaching its peak at the center. The tensile strength of the joint is slightly lower than that of the ZL114A base material, with the fracture mode characterized as low plasticity fracture. The fracture surface displays numerous flat cleavage planes, cleavage steps, and microcracks.