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6061/7075 异种铝合金静轴肩搅拌摩擦焊组织与力学性能研究

Study on Microstructure and Mechanical Properties of 6061/7075 Dissimilar Aluminum Alloys by Stationary Shoulder Friction Stir Welding

刘瑞杰¹, 潘加龙¹, 王婧薇¹, 刘佳林¹, 向家港¹, 柴福伦¹, 柴森森¹²³

Environment and Resource / 2026,8(2): 263-272 / 2026-05-26 20 18

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• Information:

  1. 重庆科技大学机械与智能制造学院，重庆；
  2. 重庆大学，重庆；
  3. 西南铝业( 集团) 有限责任公司，重庆

• Keywords:
  Dissimilar aluminum alloy; Stationary shoulder friction stir welding; Microstructure; Mechanical properties
  异种铝合金; 静轴肩搅拌摩擦焊; 显微组织; 力学性能
• Abstract: In this study, stationary shoulder friction stir welding (SSFSW) was adopted to join dissimilar 6061-T6 and 7075-T6 aluminum alloys with a thickness of 3 mm. The effects of rotational speed (400~1600 rpm) on weld formation, microstructure and mechanical properties were systematically investigated. The base materials were subjected to surface pretreatment including acetone wiping and mechanical grinding before double-sided welding, with 7075 aluminum alloy placed on the advancing side and a constant welding speed of 200 mm/min. The results show that at the rotational speed of 800 rpm, the weld surface is smooth and defect-free, and the materials in the stirring zone are fully mixed. Fine equiaxed grains with a size of 5–8 μm are formed in the nugget zone, and the Mg₂Si strengthening phase is uniformly distributed. Under this parameter, the tensile strength of the joint reaches 223 MPa (68% of the 6061 base metal) with an elongation of 5.87%, and the fracture surface exhibits ductile fracture characteristics. Excessively high or low rotational speed leads to insufficient heat input or overheating, resulting in incomplete interface fusion or grain coarsening. It is verified that the SSFSW process can effectively improve the microstructure and properties of dissimilar aluminum alloy joints by regulating the balance between heat input and mechanical stirring. 本研究针对3mm厚的6061-T6与7075-T6异种铝合金，采用静轴肩搅拌摩擦焊（SSFSW）工艺，系统研究了旋转速度（400-1600rpm）对焊缝成形、显微组织及力学性能的影响。通过丙酮擦拭、机械打磨等表面预处理后，进行双面焊接，7075置于前进侧，焊接速度固定为200mm/min。结果表明：旋转速度800rpm时，焊缝表面光滑无明显宏观缺陷，搅拌区材料混合充分，焊核区形成5-8μm的细小等轴晶，Mg2Si强化相均匀分布；此时接头抗拉强度达223MPa（6061母材的68%），延伸率5.87%，断口呈现韧性断裂特征。过高或过低的转速会导致热输入不足或过热，引起界面未融合或晶粒粗化。研究表明，SSFSW通过调控热输入与搅拌作用的平衡，可改善异种铝合金接头组织与性能。
• DOI: 10.35534/er.0802036 (registering DOI)
• Cite: 刘瑞杰，潘加龙，王婧薇，等．6061/7075异种铝合金静轴肩搅拌摩擦焊组织与力学性能研究［J］．环境与资源，2026，8（2）：263-272.