New-age materials and technologies for reducing vehicle weight

by Naveen Mehta, President – Ops, Jindal Aluminium 28 Nov 2021


As environmental legislation globally turns stringent, lightweighting metal is a crucial element that will enable original equipment manufacturers (OEMs) in the automotive sector to continue and meet emission targets. The desire to have lighter cars directly results in weight and fuel consumption, improving mileage and reducing CO2 emissions.

In modern-day automobiles, and now moving to electric vehicles (EVs), research and development have offered advanced materials that play an essential role in boosting the fuel economy while ensuring that safety and performance are well maintained. Like they say in the automobile industry, it takes less energy to accelerate a lighter vehicle than a heavier one; lightweight materials increase vehicle efficiency and thus provide more potential. 

When we talk of fuel economy improvement, a 10 percent reduction in vehicle weight can lead to a 6-8 percent benefit. The use of lightweight materials like aluminium in an automobile by replacing cast iron and traditional steel components perfectly meets the requirements of reducing weight, fuel consumption, and greenhouse gas emissions.

Aluminium, known for its versatility, strength, flexibility, malleability, conductivity, reflectivity, and corrosion resistance, fits the lightweight and other capabilities that OEMs look for in the global automotive space. Hence, in the automotive industry, hybrid and lightweight design solutions are being integrated into almost all vehicle components as applications for lightweight materials significantly reduce CO2 emissions. It can be achieved through considerable weight reductions in vehicle design.

Aluminium leading the way
As a mass reduction material, aluminium has great potential given that its 2.7 grams per cubic centimetre is less than half of iron at 7.8 g/cm3 and copper at 8.9 g/cm3. Besides, even in specific performance metrics like mechanical strength and stiffness, aluminium is better suited among new-age metals in designing vehicle components. In almost all cases involving the engine, radiators, wheels, bumpers, suspension parts, engine cylinder blocks, transmission bodies, or body parts like the hoods, doors, and even the frame, aluminium has ensured that desired performance criteria are met. This is spread across the vehicle, with even the steel body being replaced by aluminium in every possible way, even in the unibody. Aluminium and its alloys are the best bet given that they are also easy to cast, forge, machine, roll and extrude.

Besides weight reduction by direct material substitution practices, there are other additional methods that ensure component lightweighting. These include specific fabrication techniques using aluminium alloys with multi-hollow extrusions or thin-walled, high-strength, and vacuum die castings that enable new design solutions using the latest developments in technology. What helps aluminium realise its leadership position is that its use in vehicles leads to additional steps towards achieving the desired weight-saving while keeping or increasing the vehicle size. The new levels of aluminium-intensive lightweight construction in automobiles are delivering a much better fuel economy. Some of the most fuel-efficient vehicles in the world rely on aluminium in their automotive designs. Today, as hybrids and fully electric vehicles increasingly find takers, heavy battery power is no longer a requirement. Any aluminium-intensive vehicle would need less battery power but still be able to carry more payload efficiently while saving on fuel costs.

Improving vehicle fitness
For every 10 percent weight reduction gained using aluminium against steel, a 5-7 percent realisation of fuel savings is a possibility. And beyond this, a decrease in weight using aluminium brings in the possibility of using smaller and more efficient automobile engines that offer a smaller-sized fuel-efficient multi-speed transmission system. In EVs, the use of aluminium helps increase the driving range by roughly the same proportion as it reduces weight. Thanks to aluminium, the lighter an EV, the longer it will take you on a single charge. Hence, using aluminium is essential for internal combustion engine (ICE) vehicles to reduce emissions and get more out of every drop of fuel. It's the same for EV manufacturers who are working hard to increase vehicle range from a single charge.

Given the benefits of saving vehicle weight that it offers, aluminium is expected to lead innovations using new-age materials replacing steel and other heavier metals in the average car. One of the concerns while replacing the heavier metals is safety. The tensile strength, structural rigidity and corrosion, and thermal resistance remain crucial properties of aluminium in manufacturing automotive components. Research and development using downstream aluminium have resulted in a renewed push for developing new materials that led to exploring cost-effective alternatives and developing new assembly processes.

Meeting the challenges
There is no dispute that the most crucial issue facing the automotive sector today is lightweighting. The downstream aluminium industry has its foot on the pedal, developing solutions that address the need to offset weight from new features, additional safety needs, and the move to electric-powered vehicles. While carbon-fibre composites, high-strength steel, magnesium, titanium, and various foam, plastic, rubber, and natural fibres such as bamboo and kenaf are being tried, aluminium is the more popular choice that is driving the industry. Combining strength with ductility in automotive applications is a key-performance parameter that aluminium alloys have achieved remarkably.

Research and development of aluminium alloys, which began in the early 1900s, has gone a long way in enhancing its inherent properties and set the stage for the wide variety of uses it has today. Towards meeting these goals, the downstream aluminium segment is working closely with OEMs and suppliers in the automotive industry to develop lightweight materials for the body, chassis, interior, powertrain, and under-the-hood applications. New achievements of aluminium-intensive lightweight construction are therefore also projected to deliver fuel economy. For instance, additional weight-saving measures of having a smaller engine or a smaller fuel tank would fulfil requirements of acceleration and mileage per tank filling.

Cutting-edge research and development in aluminium technology has led to optimised aluminium solutions, the introduction of aluminium alloys with improved properties being developed as new design concepts.

Offering better forming and joining technologies for the automotive industry, these new-age materials and technology offer significant additional weight reduction potential through the use of tailored blanks and roll-formed profiles. The use of aluminium in making automobiles has addressed the three main elements of car makers — aerodynamics, weight, and engine. The best part of how aluminium meets these challenges is that it can be engineered to be as strong if not stronger than traditional metals like steel.

Looking at the future, experts predict that automakers will continue creating newer alloys that will help increase the adoption of low weight, high-strength aluminium at a much faster pace than ever seen before. Amid consumer pressure and growing environmental challenges, aluminium has already confirmed its position as the fastest-growing automotive material globally. With EVs being adopted broadly, the demand for aluminium extrusions and high-pressure aluminium die-cast parts continues to grow, helping automakers align to new mobility trends that offer a safe and enjoyable drive, which is also better for the protection of our environment.


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