The transportation sector commands nearly one-third of global energy demand, which translates into a vast swath of energy saving opportunities. The most promising avenue to tap these opportunities is to enhance operating efficiency with lighter structural materials – including advanced high-strength steel (AHSS), aluminum (Al), magnesium (Mg), and carbon-fiber reinforced plastic (CFRP).
This week’s graphic comes from a recent Lux Research report, in which analysts conducted decision-tree analyses of where these materials are most likely to flourish in automotive (shown here) and aerospace over the next decade.
Material selection depends on the performance requirements of a component’s location and functional role in the automobile. These roles generally fall into one of three categories: body and exterior, interior, and powertrain.
For example, body and exterior applications rely heavily on AHSS and Al, and will continue to rely on them in the future. Both materials are sturdily entrenched in primary structure applications, including the front rails and crash boxes, pillars, door beams, and chassis. All of these parts must meet extremely rigorous safety standards for high ductility and elongation, and AHSS and Al meet these standards.
Al shines in exterior automotive components that must deliver top aesthetics, a Class A surface finish, and resistance to corrosion. While technical improvements are expected across all materials, Al is the current and future leader for the roof, hood, decklid, body panel outers, outer bumpers, fender, and door outers.
AI also leads the pack for non-primary structural body components that do not require a Class A finish, including floor panels, roof panels and rack, and the structural inners of the body panels, door, trunk, hood, and decklid. AHSS is also well-established in this category. But, CFRP is gaining due to its extremely high specific stiffness, which allows for construction of thinner components.
Opportunities await Mg in the interior of the vehicle, where semi-structural components – including parts of the seat, the instrument panel support beam, and the backseat head panel – are not in the primary crash path, and therefore do not require the same ductility and inspection requirements as exterior parts. But, the familiarity and lower pricepoints of AHSS and Al will make these current frontrunners difficult to overtake.
Lastly, for powertrain components demanding high thermal stability, Al leads the way, but Mg is hot on its tail. The battery box, engine cradle, engine mounts, and transmission tunnel all need to withstand hot engine temperatures without losing their strength and structure. AHSS and Al are the current frontrunners. But Al’s lighter weight gives it the edge. While high performance thermoplastics allow them to survive higher temperatures, they are generally too expensive for the auto industry’s taste. Mg’s comparatively higher price tag has given it a slow start as well. But its adequate high temperature performance, light weight, and anticipated processing improvements and cost reductions will increase its traction in this segment in the years to come.
Source: Lux Research report “Structural Navigation: Optimizing Materials Selection in Automotive and Aerospace.”