Laser-assisted property gradients in multi-layered aluminum

The Accumulative Roll Bonding (ARB) process enables manufacturing of multi-layered aluminum sheet metals with outstanding mechanical properties. However, a significant increase in strength is accompanied by a reduced ductility. Besides, delamination effects can occur during forming operations. Therefore, property gradients will be applied by short-term laser heat treatment according to the Tailored Heat Treated Blanks technology to enhance the formability and to enable the production of components. These gradients can be realized across the plane and in thickness direction of a blank. In this paper, property gradients in thickness direction are applied to multi-layered aluminum sheet metal with nanocrystalline grain structure produced in the ARB process. Furthermore, the effect of different process parameters on the shape of the heat affected zone is presented. The property gradients are characterized using micro hardness tests. Finally, the enhancement of the formability is proven using air bending tests. (C) 2014 Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license.