Hybrid Technologies for Joining Ultra-high-strength Boron Steels with Aluminum Alloys for Lightweight Car Body Structures

Abstract Lightweight design in car body engineering enables the reduction of energy consumption and greenhouse gas emissions of cars, which is crucial to fulfill the increasing legislative restrictions and market demand for eco-friendly mobility. The challenge is to realize more lightweight and at the same time still rigid and crash-stable car bodies, that are affordable for a large-scale production. For cars for high volume markets, an intelligent load-oriented multi-material design with intensive use of ultra-high-strength hot-stamped boron steels combined with modern aluminum alloy sheets and cast is often the optimal solution, as these materials offer a great weight reduction potential at reasonable costs. The lack of suitable cost-efficient joining technologies for these material combinations is one of the most important barriers for the realization of affordable cars in volume productions. This paper presents and overview about recent developments and research results for suitable joining technologies.