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研究小搅拌针形状对6061铝合金搅拌摩擦焊接头的显微组织和力学性能的影响。采用3种不同形状的搅拌针:螺纹锥形圆柱形(T1)、三角形(T2)和正方形(T3)。结果表明:不同形状的搅拌针会显著地影响焊接接头的性能。相对于使用其他形状的搅拌针,使用三角形搅拌针能获得最好的冶金和力学焊接性能。此外,使用正方形搅拌针制备的搅拌摩擦焊接头具有最低的拉伸强度和显微硬度。更小的搅拌针形状和轴肩直径导致热影响区域变窄和一定程度的软化。断口分析结果表明,不同形状的搅拌针焊接也能影响接头。断裂面显示三角形搅拌针制备的样品在拉伸试验中以韧性断裂形式失效,而在用其他形状的搅拌针(T1和T2)制备的接头中观察到了脆性断裂。
The effect of small pin shape on the microstructure and mechanical properties of 6061 aluminum alloy friction stir welded joint was studied. Three different shapes of pin: Threaded cylindrical (T1), triangle (T2) and square (T3) are used. The results show that the different shape of the pin will significantly affect the performance of welded joints. Triangular needles provide the best metallurgical and mechanical weldability over other types of needles. In addition, friction stir welded joints prepared using square pins have the lowest tensile strength and microhardness. The smaller pin shape and shoulder diameter result in a narrowing and some softening of the heat affected zone. Fracture analysis results show that different shape of the pin welding can also affect the joints. The fracture surface shows that the sample prepared with the triangular pin failed in the ductile fracture in the tensile test whereas the brittle fracture was observed in the joint prepared with the other shaped pin (T1 and T2).