The microstructure and mechanical properties of aluminum/steel welded joint by FSLW

Abstract

Friction stir lap welding experiments between 6061 aluminum alloy and DP590 dual-phase steel plates were carried out. The effects of welding parameters and the addition of Cu foil interlayers with 0–0.3 mm thickness on the microstructures and mechanical properties of the lap joints were investigated. The shear strength of the joint reached the maximum value of 5337 N and showed a mixed ductile-brittle fracture mode when the welding speed, the rotating speed, and the thickness of the Cu foil intermediate layer were set to 80 mm/min, 900 rpm, and 0.1 mm, respectively. The plastic Al₂Cu and AlCu intermetallic compounds formed through Al and Cu reaction at the aluminium alloy/steel interface play a beneficial role in the Cu-added joint strength.

KEYWORDS:

• Aluminium alloy
• dual-phase steel
• friction stir lap welding
• Cu foil interlayer
• intermetallic compounds
• microstructure
• mechanical property

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Special Funds for Guiding Local Scientific and Technological Development by the Central Government of China (No. 2019ZYYD015), the Doctoral Research Start-up Fund of Hubei University of Technology (No. XJ2021009402), the Youth Talent Project of Science and Technology Research Program for Education Department in Hubei Province (No. Q20311412) and the Educational Reform Research Project for Postgraduate Students of Hubei University of Technology (No. 2022050).