GOALI: Retrogression Forming of High-Strength Aluminum Alloys

University Of Texas At Austin, Austin TX

Investigators

Abstract

Weight reduction is a very important means for increasing the efficiency of future automobiles and trucks. Reduced weight provides improved fuel efficiency and improved driving range, regardless of the chosen power train. When high-strength materials are used, weight reduction may be accomplished without sacrificing vehicle safety. High-strength aluminum alloys offer the potential to significantly decrease vehicle weight without compromising safety, but this potential is currently limited by the great difficulty of forming these materials into the complex component shapes needed for vehicle production. This Grant Opportunities for Academic Liaison with Industry (GOALI) award supports research on a new, unique manufacturing route to significantly improve the formability of high-strength aluminum alloy sheet materials. This route, called retrogression forming, combines forming and heat-treating operations to improve material ductility while achieving high strength in the final component. Laboratory experiments and numerical modeling will be used to establish the fundamental scientific understanding required to enable retrogression forming technology. This project will be conducted by a team that includes researchers from both industry and academia with students to be educated and trained through project activities. The collaborations between industry and academia will broaden the representation of underrepresented groups and enhance the education and training of students. Future industrial implementation of retrogression forming technology is expected to improve vehicle fuel efficiency, increase vehicle range and reduce green-house gas emissions while maintaining or improving vehicle safety. This GOALI award supports research to understand deformation during retrogression forming. Retrogression forming is a new manufacturing route aimed to increase the ductility of high-strength aluminum alloy sheet materials during forming while enabling the retention of high strength in the final components formed. For retrogression forming, a warm temperature is used to increase ductility while forming, and the forming conditions are chosen to simultaneously produce a retrogression heat treatment. Peak-aged strength can then be reclaimed easily by a modest re-aging treatment after forming. Retrogression forming offers a much more attractive approach to forming high-strength light alloys than do currently available technologies, all of which require a very high forming temperature, multiple heat treatments or both, rendering them economically unattractive. New scientific understanding for retrogression and aging kinetics and for plastic flow at warm temperatures will be established to support the development of retrogression forming technology. The research approach combines laboratory experiments, materials characterization and numerical modeling. The new scientific understanding produced will be captured in predictive numerical models useful for designing retrogression forming processes. The project seeks to ultimately demonstrate these capabilities through the forming of laboratory-scale demonstration components.