12 Jul 16 Automotive shifting to lightweight base materials
The automotive industry is likely to continue to see significant material substitutions going forward. All the stakeholders – OEMs, component suppliers and material suppliers will be active participants in this evolution.
Automotive engineering plays a significant role in improving performance of vehicles, cost reduction, and addressing regulatory mandates. At the same time, OEMs and their suppliers need to optimise on sustainability metrics such as consumption of natural resources, waste treatment and carbon emissions; and also maintain safety standards at production locations.
Engineers have been exploring innovative material substitutions to gain better efficiencies. We have already seen that aluminium, plastics, and composites have gradually replaced steel over the last few decades. The usage of these materials has evolved over a period of time in response to the changes in material availability and prices.
Until recently, all-aluminium bodies were only seen in luxury and high-end vehicles. In the last decade or two, a lot of luxury cars and SUVs have followed suit. From close to 10% currently, the average aluminium content in cars in North America is set to increase to 19% of a car’s curb weight by 2025, according to a study by Ducker Worldwide. Aluminium companies like Alcoa and Constellium see this as a big opportunity.
In order to protect their own businesses, steel companies such as ArcelorMittal, SSAB, and AK Steel have developed improved or specialty steels for the automotive sector. We are now seeing specialty steel replacing aluminium in cars!
As compared to aluminium, plastic offers further advantages of relatively superior chemical resistance, and better recyclability, making it preferable for automotives. Moreover, migrating to plastic does not require the suppliers to make large investments. The problem with plastic is that it is a petrochemical product and hence dependent on a depleting resource.
Carbon composites have arrived as a strong alternative in the auto industry
Carbon composites, a relatively new material on the block, are 30% lighter than aluminium, and stronger. Carbon composites as a replacement for metals in cars save 50% on energy and 30% on water in assembly units. Despite these advantages over metals, usage of composites is restricted to high-end cars where there is demand for light weight and high speed.
Auto companies and composites producers have recently begun forging partnerships for incorporating carbon composites vehicles. These include BMW and carbon fibre manufacturer SGL Group JV for developing carbon-fibre-reinforced thermoplastic (CFRP) body components for the BMW i3 and the BMW i8; Toray and Daimler; Audi & Voith; GM and Teijin, and so on.
Weight reduction, fuel efficiency, better strength-to-weight ratio, and stricter regulations have been the major reasons to opt for material substitution over the years. The diagram below shows the weight reduction potential and relative prices of different materials as compared to steel.
Since the new materials cost more than the existing ones, material substitution is likely to start with luxury and high-end cars.
The materials of the future are likely to be superior high-strength steels, duraluminum, carbon-fiber reinforced plastics, graphene, magnesium alloys, and biomaterials. The key components impacted by substitution will be car bodies, interiors, bumpers, seats, doors, and safety accessories. There are many other materials that are being researched for their suitability in automotive, such as magnesium alloys, biomaterials and graphene.
As components of new and varied materials are developed, a key challenge will be to effectively assemble and bond these materials to one another. There is a growing demand for superior adhesives, and fast-curing and reliable resins for use in short production cycles. For example Henkel has developed a new adhesive – Loctite UK 2015 – which is ideally suited for use on structural body parts, regardless of whether they are made of fibre-reinforced plastics, e-coated steel or e-coated aluminium.
Suppliers of materials are increasingly taking up the technological initiative for innovation and R&D in materials for automotive. The OEMs’ share of global R&D value creation is expected to decline from 60% today to less than 50% by 2025; at the same time suppliers and engineering service providers will notch up theirs.
Component manufacturers will also need to participate in this evolution. They will have to be proactive in incorporating the emerging materials if they want to protect their businesses.
We will explore some of the emerging materials, and the components that they could be used for, in our forthcoming blogs.