Aluminium in the automotive industry

A modern car with components made of aluminium can be 24 percent lighter than one with components made of steel, which also allows fuel consumption to be reduced by 2 litres per 100 kilometres.

Car manufacturers first started to use aluminium over a hundred years ago. Back then aluminium was a new and a poorly explored metal, however its light weight and corrosion resistance showed the metal’s great potential for application in the emerging automotive industry. The first sports car featuring a body made of aluminium was presented to the general public at the Berlin international motor show in 1899. The first engine with aluminium parts was made two years later, when in 1901 Carl Benz, later a world-famous manufacturer, presented a new car for the prestigious race in Nice. The ‘light metal’ added to the handling of the car, but difficulties in metal working, lack of knowledge and its high price impeded the use of aluminium in mass car production in the beginning of the century.

It was only after the war with aluminium becoming more accessible and cheaper, that the British company Land Rover started an in-depth exploration of the properties of ‘winged metal’. In 1961 the company presented and later launched into mass production the Buick 215 with an eight-cylinder V8 engine. Cylinder blocks of this engine were made of aluminium. With a weight of only 144 kg the engine was a real breakthrough. It immediately became popular among race-drivers. It was light and allowed for a considerable advantage during acceleration. When in 1962 the legendary American racer Mickey Thompson drove a car with an engine made of the light-weight metal during the ‘Indianapolis 500’, the engine demonstrated great performance. In the course of time many companies improved this legendary engine to use it in mass-produced models and race cars, including in Formula-1 cars.

When in the seventies the oil crisis broke out, car manufacturers began to search for ways to reduce fuel consumption. The best method was to reduce the weight of the vehicle. The calculations showed that reducing a medium-sized car’s weight by 100 kg would result in a saving of 700 litres of fuel during the vehicle’s lifetime. Thus, car manufacturers started to replace numerous car units with those made of aluminium, therefore reducing the total weight of vehicles. Today, an average of 110-145 kg of aluminium is used in production of an average car, a figure which continues to grow with every year.

Advanced high-tensile aluminium alloys can now completely supersede steel that has conventionally been used to make a vehicle body, the most important car component. This was proved by Audi engineers, who in 1994 released a passenger A8 model with the complete body made of aluminium. The model showed a weight reduction of 239 kg!

Audi has been studying aluminium applications for 20 years by intensive R&D projects. Release of the ASF space frame marked the birthday of a high-duty aluminium frame structure with embedded large aluminium panels that absorb a part of load. Stamped aluminium panels are connected with multifunctional cast elements. This new structure also required new technologies to be applied. For this purpose, new light alloys and material treatment technologies were developed.

First produced in 1997, aluminium body cars were a riot even among the Audi fans. Today, all-aluminium bodies are installed on Audi A2 (advanced design) and A8 (updated design) models. According to the information from the company’s Russian representative office, 133,000 of A2 and 117,000 of A8 have been produced since 1993.

A new generation of offroader Land Rover Range Rover will also have an important difference from its predecessor, namely an aluminium body. Although Ford, the parent company, has not officially approved completion of this technology for Range Rover, sources from within the company believe the approval will be granted in the coming months. One of the sources made a following comment, ‘We’re just waiting here to be told: OK, guys, get it on!’ An aluminium body will help to reduce Range Rover’s weight by about 300-400 kg as compared to the current model. However, in Land Rover’s lineup this car will still remain the most pompous and presentable with the most spacious and exquisite interior. An aluminium body will also allow for the fuel economy to be improved, the CO emissions to be reduced. Dynamics and handling behaviour are also expected to improve.

Mazda engineers have designed a revolutionary idea of welding together aluminium and steel that will be first utilised in industrial production of parts for the new model of RX-8 sports car. So far it was considered impossible to weld aluminium and steel together.

Mazda engineers resolved this task by heating up upper layers of aluminium by attrition (like in a microwave oven), with simultaneous galvanising of welding surface of steel. The corrosion process enables aluminium particles to penetrate the structure of steel and form a reliable adhesion. The new cutting-edge technology opens broad prospects for the automotive industry to produce combined aluminium-and-steel bodies for cars with partial use of welding instead of clamps. It enhances durability and reliability of structures, making them more light-weight at the same time. Mazda specialists have obtained over 20 patents in the framework of developing the new technology.

Not so long ago Jaguar announced the birth of the first representative of its sports cars new generation — Jaguar XK model. The technology of producing the body of the car is worth giving attention to. What is unique about it is the first industrial application in the automotive industry of an integral all-aluminium ‘monocoque’-type body. Having developed aviation technologies where light-weighting is the critical factor, Jaguar managed to introduce the light and durable body design, some parts of which can be fasten together both by clamps and epoxy adhesives, for batch production.

BMW 5-series was designed actively using aluminium parts — the ‘winged metal’ served as the material for nearly all elements of the fore carriage. According to specialists, such a decision was inspired by the wish of BMW engineers to decrease the overall weight of the car and at the same time to even out its distribution by axes. This decision will have a positive effect on the car driveability.

Today aluminium is the second most used material (in percentage terms) of the total weight of the car. It is used to make components of the suspension, the chassis, cylinder blocks and other engine components. It is believed that 1 kg of aluminium can replace up to 2 kg of steel and cast iron in many areas of application.

The more aluminium is used in the production of a vehicle, the less the weight of the vehicle is and the less fuel it consumes, thereby reducing the amount of harmful emissions into the atmosphere. The calculations showed that in 2006 the automotive industry output reached 65 million vehicles. If during manufacturing of each of these vehicles their bodies, engines and other components had been made of aluminium instead of steel, the CO2 emissions into the air would have been reduced by 140 million tonnes, and the total fuel economy during the lifetime of all vehicles would have allowed to save 60 billion litres of crude oil.

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