Investigation of dry lubrication systems for lightweight materials in hot forming processes

Abstract

In the automotive industry, growing demands for lightweight solutions lead to new materials and forming methods. Because of the high specific strength and low density, high-strength aluminum alloys like 7xxx series have a big potential for safety-relevant components, in the future. With the help of thermal supported forming operations like hot forming and quenching, complex part geometries are realizable. The high formability compared with the lower forming forces and reduced springback, as well as a subsequent hardening step enables the production of complex parts. Currently, this forming process is reaching its limits because of high adhesive wear during forming. Therefore industrial use is not suitable at the moment. New developed dry lubrication systems enable hot forming operations without the generation of toxic emissions and a reduction of the adhesive wear. Therefore, different dry lubricants with varying particle size have been analyzed for deep drawing operations under quenching conditions. The influence of the particle size on the applicable lubrication thickness and the necessary consumption has not been analyzed before. Aim of this research is the characterization of different dry lubricant particle size distributions for hot forming and quenching of high-strength aluminum alloys.