Joinability and Mechanical Properties of Clinched Joints of Different Aluminum Alloys

• DOI: 10.1007/s12541-021-00582-2
• Publication Date: 2021-09-23T11:50:16Z
• Authors: Yue Zhang; Honghe Xu; Ruitao Peng; Yan Lu; Linwei Zhu
• Keywords: 0209 industrial biotechnology; 0203 mechanical engineering; 02 engineering and technology

The joints of four aluminum alloy (7075, 5754, 6061, 1060) sheets were prepared using the clinching process with different die assemblies, and the forming and mechanical properties of the produced joints were evaluated using different testing procedures. The neck thickness, undercut values, bottom thickness, and joint dimensions of the joints were measured to investigate the joinability. The forming quality parameters, strength, failure displacement, failure mode, and energy absorption of the joints were investigated using the tensile shear test and peeling test. It was revealed that all four aluminum alloy sheets could form clinched joints with a suitable undercut, neck thickness and different die fits. A combination of SR5202 and SR703.12 dies resulted in an optimum joint quality for different sheets. Both neck thickness and the undercut amount played a major role in the determination of the strength of the joints. The best mechanical properties of the single-lap and cross joints were found for the sheets made from aluminum alloys 7075 and 6061. The aluminum alloy 5754 clinched joints exhibited slightly deteriorated mechanical properties but had the highest energy absorption capacity of the joints. However, the lower yield strength of aluminum alloy 1060 led to poor mechanical properties of these joints. All the single lap joints showed a tensile-shear failure mode of the upper sheet material, whereas the peel failure modes of the cross joints showed neck pull-off failure, neck fracture failure, and neck mixed failure.