2219铝合金与不锈钢惯性摩擦焊接接头组织与力学性能

Microstructure and mechanical properties of inertia friction welded joint between 2219 aluminum alloy and stainless steel

异种金属的连接可实现节能、经济及减重的目标,成为航空航天、造船、铁路运输等领域的研究热点之一;而铝合金与不锈钢物理化学性能差异明显,成为异种金属中最难实现的连接接头之一。采用惯性摩擦焊接技术进行2219铝合金与不锈钢回转体的连接,分析不同焊接工艺参数下铝钢惯性摩擦焊接接头的显微组织与力学性能。结果表明,惯性摩擦焊接使铝钢接头铝合金一侧形成了细晶区和拉长晶区;EDS结果显示焊接界面处发生了Fe、Al等元素扩散。硬度测试结果表明,在连接界面处-0.6^+0.15 mm范围内硬度值发生了明显的阶跃变化,该区域为受焊接热及变形作用的主要区域,硬度值高于母材。合理焊接工艺下获得的2219铝合金与不锈钢接头拉伸强度为235~300 MPa。铝钢惯性摩擦焊接断口以脆性断裂为主。

Dissimilar metal joining can achieve the goal of energy saving, economy and weight saving, and receives considerableattention in the field of aerospace, shipbuilding and railway etc. Since aluminum and steel demonstrate have different physicaland chemical properties, it is difficult to gaina good joint. Inertia friction welding is used to join 2219 aluminum alloy and 304stainless steel, and the microstructure and mechanical properties of inertia friction welded joint are analyzed under differentwelding parameters. The results show that the microstructure of aluminum alloy side is divided into fine -grain are andelongated -grain area. The EDX results display that diffusion of elements iron and aluminum is observed on the weldinginterface. The hardness test shows that the hardness makes a step change on the interface within the scope of -0.6- ＋0.15 mm,which is the main area affected by friction heat and deformation, and the hardness of this area is higher than that of base metal.The tensile strength of joints are from 235 MPa to 300 MPa using the optimized parameters. The fracture of this inertia frictionwelding mainly appears brittle fracture.