ALUMINUM COMPOSITE MATERIAL AND FORMING METHOD

摘要

The invention relates to a method for forming an aluminum composite material which has a core alloy made of an aluminum alloy of the type AA5xxx or AA6xxx and at least one outer aluminum alloy layer provided on one or both sides. The aluminum composite material is formed in a forming tool, and the outer aluminum alloy layer provided on one or both sides has a yield strength Rp0,2 of 25 MPa to 60 MPa in the soft- or solution-annealed state. The aim of the invention is to extend the forming limits of AA6xxx und AA5xxx aluminum alloys which are of interest in the automotive industry and to provide a forming method which allows the production of heavily formed large-surface aluminum alloy sheet metal parts, in particular even exterior surface-quality sheet metal parts. This is achieved in that k,f,outside/kf"core < 0.5 applies to the yield stresses of the aluminum alloys of the core and of the at least one outer layer in the soft- or solution-annealed state, and the frictional shear stress TR between the tool and the aluminum composite material in the contact surface reaches the shear flow stress koutside of the outer aluminum alloy layer at at least one local position in the forming tool during the formation of the aluminum composite material.