Microstructure and mechanical properties of thin aluminum alloy by friction stir welding

DOI:	10.11809/bqzbgcxb2023.11.028
Keywords:	5052 aluminum alloy; friction stir welding (FSW); mechanical properties; microstructure; “S” lines
Abstract:	Friction stir welding test of 5052 aluminum alloy with a thickness of 2 mm is carried out by single and double side welding. The microstructure, microhardness, tensile properties and fracture morphology of the joint are studied. The results show that there are ‘S’ lines inside both single and double side welding joints, and double side welding could effectively improve the distribution of ‘S’ lines and avoid weak connections at the bottom of single side welding; The transverse microhardness of both single and double side FSW weld sections show a ‘W’ shape, and the microhardness gradually decreases along the thickness direction. The highest microhardness along the thickness direction is 68.4 HV and 84.2 HV for single and double side welding, respectively. The grain size of the double side welding seam is more refined; The average tensile strength of single and double side welding is 198 MPa and 210 MPa respectively, and the mechanical properties of double side welding joints are better than that of single side welding; Through the analysis of the fracture morphology of the joint, it is found that the fracture mode of both single and double welding joints is a mixture of ductile fracture and tear ductile fracture.
Issue:	Vol. 44 No. 11 (2023)
Published:	2023-11-28
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