Mechanical Joining of the Combination of Steel Sheets and Aluminium Alloy Sheets

Abstract

Constructions of steel sheets and sheets from aluminium alloys are widely used in car body production to reduce the total car weight. The reduction in car weight is needed to improve fuel efficiency. Aluminium alloys play a more important role in future car body generations. Properties of this material give some advantages and open the way for new applications in the automotive industry. It is not possible to join the multiply material combination by conventional joining methods such as resistance spot welding. Therefore, alternative joining methods are being developed. One of the alternatives is mechanical joining - clinching. Clinching is suitable for joining the thin sheets from ferrous and non-ferrous metals. Mechanical clinching is also well known as a speed and efficient cold joining process, mainly for joining the thin-sheet applications. In this process, the local plastic deformation of the sheets is created by the clinching tool. The paper focuses on the evaluation of the properties of mechanically clinched joints, realized on the combination of the zinc-coated steel sheets DC06 and H220PD and sheets from aluminium alloys EN AW 5754 with various hardness H11, H22 and H24 and EN AW 6082. The tensile test and a metallographic observation were used to evaluate the clinched joint properties. Mechanical clinching proved to be suitable technique for joining the observed combination of steel sheets and aluminium alloy sheets. It is necessary to consider the orientation of the sheets relative to punch and die.