Research on a single-point butt clinching process with various forming forces

Abstract

With the rapid emergence of lightweight materials, the joining process of various lightweight materials has developed to a popular research spot in the engineering field. In this work, a novel type of butt form based on the mechanical clinching process was proposed, which is a single-point clinching process. This method contributed to simplify the clinching process while increase the joining efficiency and produce higher economic benefits. The forming forces of 25, 30, 35, 40 and 45 kN were exerted to produce the dissimilar single-point butt joints. In addition, main geometrical parameters of the mechanical interlock structure, static mechanical properties, SEM morphology of the fracture surface and failure details of dissimilar joints were analyzed by experimental method. The experimental results indicated that both static strength and energy absorption capacity of the single-point butt joint produced by AA5052 sheets are proportional to the forming force in the range of 25–45 kN. The single-point butt joint produced with 45 kN forming force has the most outstanding performance on static shearing strength (1014.2 N) and energy absorption value (0.825 J). Neck fracture is the main failure mode during the static strength test in this work. Furthermore, microscopic morphology of the fracture surface on AA5052 single-point butt joint indicates that ductile fracture is the mainly failure form, and the large number of dimples facilitate the absorption of the energy during the fracture process. The process proposed in this work is particularly suited to components that cannot meet the length requirements of the lap form and are subject to comparatively small shearing force.