Effects of technological parameters on microstructure and properties of self-piercing riveting joints of 5182-O aluminum alloy sheets

Under the actions of D-die and F-die, four lengths of rivets (5.0 mm, 5.5 mm, 6.0 mm and 6.5 mm) were used to conduct self-piercing riveting tests on the joints of 1.5 mm+1.5 mm 5182-O aluminum alloy plates. The key characteristic values were measured on the profiles of the joints. The microstructure and mechanical properties of the joints were studied by using EBSD, hardness tests and tensile tests. Based on the constitutive models of 5182-O plates under different strain rates and the Johnson-Cook damage model, the forming process of self-piercing riveting was established and the simulation results were compared with the experimental results for verification. The results show that the mechanical properties of the joints increase firstly and then decrease with the increase of rivet length. When the length is 6.0mm, the mechanical properties of the joints are optimum. Under the same length of rivet, the mechanical properties of joints in group D are significantly higher than those in group F. The degree of deformation in group D is obviously higher than that in group F, resulting in higher work-hardening capacity. Software DEFORM-2D was adopted to establish the forming model of self-piercing riveting. The simulation results show an error of less than 15%, compared with the results by experiment, which verifies the accuracy of the model. © 2021, Science Press. All right reserved.