采用阳极氧化法在7050铝合金表面制备了两种厚度的氧化铝薄膜, 再用搅拌摩擦焊对铝合金进行焊接, 研究了表面氧化膜厚度对焊接接头性能的影响。结果表明, 氧化膜厚度对焊接接头性能的影响与焊接参数密切相关, 当氧化膜厚度为12.7μm, 焊速为50mm·min-1, 搅拌针转速为600~800r·min-1时, 接头的抗拉强度十分接近表面为自然状态接头的, 而当氧化膜厚度为44μm 时, 接头焊缝氧化物含量增多, 接头强度与自然状态接头的强度相比大幅降低;氧化膜提高了焊核区的硬度, 膜厚度为44μm 时焊核区硬度最高达265HV, 最低约180HV。

The anodic oxidation method was adopted to prepare alumina film with two sorts of thickness on the surface of 7050 aluminum alloy, and then to weld by friction stir welding. The effect of surface oxidation film thickness on property of welded joints was studied. The results show that the effect of surface oxidation film thickness on property of welded joints was closely related to the welding parameters. When the thickness of oxidation film was 12.7 μm, welded speed was 50mm·min-1 and the rotation rate of stirring pin was 600-800 r·min-1, the tensile strength of joints was close to the joint of natural state surface. But when the thickness of oxidation film was 44 μm, the oxide content in weld seam raised and the tensile strength decreased prominently. The surface oxidation film increased the hardness of the welded core zone, the highest and lowest hardness value was 265 HV and 180 HV respectively when the film thickness was 44 μm.