铝合金搅拌摩擦焊拼焊板焊缝各区力学性能的差异导致拼焊板成形时严重的不均匀性,降低了拼焊板的成形性能,极大地限制了铝合金拼焊板的应用。以2024铝合金搅拌摩擦焊拼焊板为研究对象,通过实验和有限元模拟系统研究接头力学性能失配对铝合金拼焊板塑性成形性能的影响规律和机理。对铝合金搅拌摩擦焊接头进行金相检验和硬度测试,根据接头组织及硬度分布特征,将搅拌摩擦焊接头划分为焊核区、热机影响区、热影响区以及母材区4个部分,以此建立搅拌摩擦焊接头的有限元模型,并对接头变形过程中的约束与协调变形规律进行分析。接头变形时拉伸应力在屈服应力最小的区域最低,在屈服应力较大的区域相应升高,且在接头中存在失配比交界处都会发生突变。从形变能的角度分析,这主要是由于力学性能失配而导致变形不协调及相互约束,表现在接头拉伸性能上就是屈服强度及屈服位置、抗拉强度、延伸率随接头各区失配比组合的差异。 The differences in the mechanical properties of the welding seam of the aluminum alloy friction stir welding tailor welded plate lead to the serious inhomogeneity in the tailor welded plate forming, which reduces the forming performance of the tailor welded plate and greatly limits the application of the tailor welded aluminum alloy plate. Taking 2024 aluminum alloy friction stir welding tailor-welded plate as the research object, the influence law and mechanism of the mechanical performance mismatch on the plastic forming performance of aluminum alloy tailor welded plate were studied through the experiment and finite element simulation system. According to the microstructure and hardness distribution characteristics of friction stir welded joints, the friction stir welded joints were divided into four parts: weld zone, heat affected zone, heat affected zone and base metal zone The finite element model of the friction stir welded joint was established and the rules of the restraint and the coordinated deformation in the joint deformation process were analyzed. When the joint is deformed, the tensile stress is the lowest in the region with the smallest yield stress and the corresponding region in the region with larger yield stress, and there is a mutation in the joint due to the mismatch ratio at the junction. From the deformation energy point of view, this is mainly due to mismatch in mechanical properties caused by the lack of coordination and mutual restraint, tensile performance in the joint is the yield strength and yield position, tensile strength, elongation with the joints of the mismatch ratio Differences in composition.