The importance of modern material characterisation methods in energy efficient sheet metal forming process development

The urgent need to use energy and raw materials more efficiently, forces the automotive industry into using lightweight construction materials. Lightweight materials such as aluminium, magnesium, ultra high strength steels and tailored blanks are rapidly gaining importance as weight reduction solutions. The increasing popularity of these lightweight materials poses new challenges to tool and forming process designers who are very reliant on FEM simulations. The aim of the paper is to explain the importance of modern material characterisation methods in energy efficient sheet metal forming process development. A brief summary of what material characteristics are needed for designing cold or hot forming tools are given. Stress deformation diagrams of 7025 and 7165 titanium are presented as examples of tests relevant to cold forming. Form limit curves measured at different temperatures demonstrate how increased temperature influences the formability of AA7075 T6 aluminium.