Investigation of the flat clinch–rivet process with different blank holder structures

The increasing application of novel and high-performance metallic materials poses new challenges to the problem of joining sheets. Clinching technology has become the common means of green joining in the automotive industry. The application of conventional clinching to visible surfaces in automobiles is limited by the external protrusion of the clinched joint. It cannot be ignored the important role of the blank holder in controlling the material flow in the clinching process. In this study, the joint quality of Al5052 sheets for the flat clinch-rivet process was investigated by experimental methods. A flat bottom die and rivets were used to form joints under different blank holder structures. Geometric parameters, static strength, failure modes, and energy absorption were analyzed. The results indicate the flat clinch-riveted joints created by the conical stepped blank holder have the advantages of no indentation, high energy absorption, and high joint strength. The flat clinch-rivet process should preferably use a conical stepped blank holder.