铝/铜（Al/Cu）层状复合板兼具铝合金和铜合金的双重优势，在航空航天等领域具有广泛的应用前景。采用真空电子束焊接方法对Al/Cu层状复合板进行焊接（铝层在上、铜层在下），研究不同的焊接工艺参数对焊接接头成形性能、微观组织及力学性能的影响。试验结果表明：铝层焊缝主要由α⁃Al和Al⁃Cu共晶组织组成，铜层焊缝中心为Al₂Cu和AlCu金属间化合物，边缘由Al₄Cu₉、AlCu和Al₂Cu金属间化合物组成。平行铝层和铜层处显微硬度在母材与热影响区变化不明显，铝/铜界面层处母材→热影响区→焊缝的显微硬度呈逐渐增大趋势，硬度最大为578.1 HV，垂直界面处显微硬度逐渐增大，最大硬度为590.4 HV。纳米压痕显示在焊缝上部、界面区域和下部的压痕回复率分别为6.31%、10.88%和7.84%，焊缝中心处有较高的弹性模量和硬度。焊接接头的抗拉强度最高为64.38 MPa，为母材强度的36%，延伸率为1.44%，铝层焊缝呈现为准解理断裂，铜层焊缝呈现为沿晶断裂，断裂位置发生在Al⁃Cu共晶组织和Al₂Cu的金属间化合物区域。

Aluminum/copper （Al/Cu） bimetallic composite plate has the advantages of both aluminum alloy and copper alloy， and has a wide application prospect in aerospace and other fields. In this paper， vacuum electron beam welding （EBW） method was used to weld Al/Cu bimetallic composite plate （Al layer on top and Cu layer on bottom）， and the influence of different welding parameters on the formability， microstructure and mechanical properties of welded joints was studied. The experimental results show that the weld of Al layer is mainly composed of α-Al and Al-Cu eutectic structure， the weld center of Cu layer is composed of Al₂Cu and AlCu intermetallic compounds， and the edge is composed of Al₄Cu₉， AlCu， and Al₂Cu intermetallic compounds. The microhardness of the base material → heat affected zone → weld at the Al/Cu interface layer increases gradually， and the maximum hardness is 578.1 HV. The maximum hardness is 590.4 HV at the vertical interface. The nanoindentation show that the indentation recovery rates in the upper part of the weld， the interface area and the lower part of the weld are 6.31%， 10.88% and 7.84%， respectively， and the center of the weld has higher elastic modulus and hardness. The maximum tensile strength of the welded joint is 64.38 MPa， 36% of the strength of the base metal， and the elongation is 1.44%. The Al layer of the welded joint shows quasi-cleavage fracture， while the Cu layer shows intergranular fracture， which occurs in the region of Al-Cu eutectic structure and Al₂Cu intermetallic compound.