6063铝合金双轴肩搅拌摩擦焊接头组织性能研究

进行了3 mm厚6063-T4铝合金双轴肩搅拌摩擦焊接。结果表明,当搅拌头转速为600 r/min,焊速在100~300 mm/min的范围内,可获得表面成形美观、内部无缺陷的优质接头。在接头搅拌区内,上、中、下各层硬度分布较为均匀,在热机影响区及热影响区内,上、下层硬度值高于中间层。热机影响区靠近搅拌区的位置以及热机影响区与热影响区的交界处为接头的两个薄弱位置。随着焊接速度的增加,接头各区域硬度值以及抗拉强度有着先增大后减小的趋势,所得最优接头抗拉强度为174 MPa,达到母材的87%,断裂位置位于热影响区。

Microstructure and mechanical properties of bobbin tool friction stir welded joints of 6063 aluminum alloy

Bobbin tool friction stir welding was applied to join 3 mm thick 6063-T4 aluminum alloy. When the tool rotation speed was 600 rpm and the welding speed was in range of 100 to 300 mm/min, the sound weld with good formation and without defects can be obtained. In the stir zone of the joint, the hardness is distributed uniformly. In the thermal-mechanically affected zone and thermal affected zone, the hardness at the upper and lower layers was higher than that at the middle layer. The location which was in the thermal-mechanically affected zone and near the stir zone, and the boundary between the thermal-mechanically affected zone and the thermal affected zone were the two weak areas of the joint. With the increase of welding speed, the hardness and the tensile strength of the joint firstly increased and then decreased. The tensile strength of the optimal joint was 174 MPa and the joint efficiency was up to 87%. The fracture location was in the heat affected zone.