Innovative joining technologies for lightweight material vehicles

The transport industry is one of the most important for society and its economic growth. In Europe, this is especially true for road transport, which is an essential pillar for employment, trade, and economic development. The challenge is to minimize energy and cost and maximize efficiency while ensuring comfort and safety. This is the driving force behind technological progress that with social changes (such as, changing consumer preferences, greater environmental awareness) and political changes is revolutionizing the way people and goods move. Nevertheless, the selection of lightweight materials is negligible; it could involve new manufacturing technologies and joining techniques. Jaguar Land Rover (JLR) has been one of the prominent car producers employing aluminum alloys since 2003. A typical JLR monocoque is characterized by 90% aluminum stampings components made of 5xxx and 6xxx series aluminum alloys. Audi Space Frame (ASF) represents an alternative interpretation of improved lightweight frame architecture, and it is characterized by aluminum for more than 80% with the residual parts in CFRP used for rear panels, tunnel and the components useful to higher torsional stiffness. A 30% weight decrease is reached with respect to traditional steel corresponding elements. This review shows an overview of the challenges and opportunities for automotive body structures in the coming years while maintaining the goal of reducing mass and improving sustainability without increasing costs and impacting safety. This manuscript first evaluates how we can reduce mass in vehicles minimizing the carbon footprint and developing recyclable structures. The potential of new materials will be shown in light of the design constraints and the choice of technology used. The final remarks will discuss opportunities for engineering innovation dictated by this period of great changes and needs.