Abstract The sample in center position of friction welded aluminum/copper joints has the highest tensile strength and elongation, which are 88 MPa and 20%, respectively. The tensile properties decrease with the increase of thickness of intermetallic compounds along radial direction. Fracture position transfers from aluminum side for samples from the center to the interface for samples from 1/2R and edge positions of joint. After heat treatment at 100 °C and 250 °C for 2 h, the tensile strength and elongation of samples in center position decrease and the fracture is with transgranular and faceted features, respectively. After heat treatment at 400 °C for 2 h, AlCu intermetallic compound layer forms between Al2Cu and Al4Cu9. Fracture morphology with net-like structure occurs in center position and the tensile strength and elongation decrease significantly. By comparing all fracture surfaces under different heat treatment conditions, the evolution of fracture mode in center position develops ahead of that in edge position.

中文翻译：

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铝/铜摩擦焊接头径向微观组织和力学性能的不均匀性

摘要 摩擦焊铝/铜接头中心位置的试样抗拉强度和伸长率最高，分别为88 MPa和20%。拉伸性能随着金属间化合物沿径向厚度的增加而降低。断裂位置从样品的铝侧从中心转移到样品的界面，从 1/2R 和接头的边缘位置。在100℃和250℃热处理2h后，试样中心位置的拉伸强度和伸长率下降，断口分别具有穿晶和刻面特征。在 400 °C 下热处理 2 h 后，AlCu 金属间化合物层在 Al2Cu 和 Al4Cu9 之间形成。中心位置出现网状结构的断裂形态，抗拉强度和伸长率显着下降。通过比较不同热处理条件下的所有断口面，中心位置断裂模式的演化先于边缘位置。