Butt friction stir welding between pure copper and AA5754 alloy was carried out. Reinforcing SiC nanoparticles were utilized in friction stir welded (FSW) joints to decline the harmful effects of intermetallic compounds. Tensile tests, micro-hardness experiments, scanning electron microscopy and X-ray diffraction analysis were applied to studying the properties of welded joints. The joints with a travel speed of 50 mm/min and a rotation speed of 1000 r/min showed the best results. The presence

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... f nano-sized SiC particles reduced the grain size of aluminum and copper in the stir zone (SZ) from 38.3 and 12.4 µm to 12.9 and 5.1 µm, respectively. The tensile strength of the joint in the presence of reinforcing SiC nano-particles was ~240 MPa, which is ~90% of that for the aluminum base. Furthermore, the highest microhardness of the weld zone was significantly increased from HV 160 to HV 320 upon the addition of SiC nano-particles. The results also showed that raising the heat generation in FSW joints increased the amount of Al 4 Cu 9 and Al 2 Cu intermetallic compounds. 摘 要:对纯铜与 AA5754 合金进行对接搅拌摩擦焊接。为了降低金属间化合物的有害影响,在搅拌摩擦焊(FSW) 接头中添加纳米 SiC 强化颗粒。采用拉伸试验、显微硬度试验、扫描电镜和 X 射线衍射分析方法研究焊接接头的 性能。结果显示,当焊接速度为 50 mm/min、转速为 1000 r/min 时接头的性能最好。纳米 SiC 颗粒的存在使搅拌 区(SZ)铝和铜的晶粒尺寸分别从 38.3 和 12.4 μm 减小到 12.9 和 5.1 μm。含 SiC 纳米增强颗粒的接头其抗拉强度 约为 240 MPa,是铝基体的~90%。且添加 SiC 纳米颗粒使接头焊缝区的最高显微硬度从 HV 160 显著增加到 HV 320。结果还表明,FSW 接头中生成热的升高使 Al 4 Cu 9 和 Al 2 Cu 金属间化合物的数量增加。 关键词:搅拌摩擦焊;异种 Al/Cu 接头;SiC 纳米颗粒;金属间化合物;显微组织特性;力学性能 (Edited by Xiang-qun LI)