(Department of Mechanical Engineering Science, Auckland Park Kingsway Campus,
University of Johannesburg, Johannesburg 2006, South Africa)
摘 要: 采用攪拌摩擦點(diǎn)焊技術(shù)連接純銅(C11000)和純鋁(AA1060)板材，并表征了焊縫的演變性能。在不同轉(zhuǎn)速和送入深度下，采用不同形狀刀具制備點(diǎn)焊焊縫。在焊縫兩邊可觀察到不同長(zhǎng)度銅環(huán)，這表明銅向前擠壓進(jìn)入鋁板，有助于得到高強(qiáng)焊縫。采用能量散射譜和X射線衍射研究手段可觀察到在鋁基體中存在銅粒子，且有各種不同的金屬間化合物存在。除了在轉(zhuǎn)速800 r/min下采用錐形銷和凹形肩得到的焊縫外，最大的拉伸斷裂載荷隨著送入深度的增加而增大。在剪切-拉伸載荷條件下，所有的攪拌摩擦點(diǎn)焊接頭產(chǎn)生了點(diǎn)焊熔核滑脫失效模式。在樣品鎖眼附近得到了峰值硬度，這同焊接攪拌區(qū)存在金屬間化合物有關(guān)。
關(guān)鍵字: 鋁；銅；攪拌摩擦點(diǎn)焊，顯微硬度；顯微組織
（Department of Mechanical Engineering Science, Auckland Park Kingsway Campus,
University of Johannesburg, Johannesburg 2006, South Africa）
Abstract:Friction stir spot welding technique was employed to join pure copper (C11000) and pure aluminium (AA1060) sheets. The evolving properties of the welds produced were characterized. The spot welds were produced by varying the rotational speed, shoulder plunge depth using different tool geometries. The presence of a copper ring of different lengths was observed on both sides of the welds indicating that Cu extruded upward into the Al sheet which contributed to obtaining strong welds. The microstructure showed the presence of copper particles in the aluminium matrix which led to the presence of various intermetallics observed by the energy dispersive spectroscopy and X-ray diffraction. The maximum tensile failure load increases with an increase in the shoulder plunge depth, except for the weld produced at 800 r/min using a conical pin and a concave shoulder. A nugget pull-out failure mode occurred in all the friction stir spot welds under the lap-shear loading conditions. High peaks of Vickers microhardness values were obtained in the vicinity of the keyhole of most of the samples which correlated to the presence of intermetallics in the stir zone of the welds.
Key words: aluminium; copper; friction stir spot welding; microhardness; microstructure
