With the fuel price rising higher by the day, it has become a mission for the Automakers to keep the weight of cars low and try and improve fuel efficiency of their vehicles. The attempt all around is to increase the use of lightweight aluminium, plastics, polymers and composites in the body and components of vehicles of all classes.
According to senior vice president of Novelis, Mr. Erwin Mayr, automotive materials can have an important impact on the environment. The new CAFE standards mentions that CO2 must get reduced to just over 100 grams per mile and the US government regulations have directed that the automotive companies reduce vehicle exhaust emissions, improve occupant safety, and enhance fuel economy. The pressure for car weight reduction has encouraged substitution of steel and cast iron with aluminium and plastics. According to Alcoa’s director of automotive marketing, Randall Scheps, Automaker’s effort to improve fuel efficiency in vehicle will ultimately boost the demand for automotive aluminum heavily by 2025.
Carmakers all over the world are working continuously on improving fuel standards. The engineers are involved in various R and D projects to increase aluminum content in the cars and especially in hoods and doors which take a large amount of bulk. By 2025, an average car will incorporate 250kg of aluminium compared to the 155kg in today’s vehicles. For this, Alcoa has spent $300 million in development projects at its Davenport, Iowa rolled products plant. The grey metal serves as a much lightweight alternatives to steel in cars that can help maintaining the new fuel efficiency regulations.
BMW to Audi have already started to react to the so-called Corporate Average Fuel Economy (CAFE) standards and are beginning to substitute heavier steel body frames with lighter-weight material. While use of the lightweight metal is not new with the Jaguar XJ, the new Mercedes-Benz SL is also relying on aluminium to reduce weight.
Novelis announced that the newly launched 2012 Mercedes-Benz SL uses Novelis aluminium extensively. The latest Mercedes model features an all-aluminum body structure which reduces the weight of the vehicle by approximately 140 kilograms and provides improved fuel efficiency and driving performance. Novelis is also a supplier of aluminum sheet for nine other Mercedes models.
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 liters per 100 kilometers. The latest aluminium alloys can now completely substitute steel that has conventionally been used to make a vehicle body, the most important part of a car. Today aluminium is the second most used material of the total weight of the car. It is believed that 1 kg of aluminium can replace up to 2 kg of steel and cast iron in many areas of application.
More aluminium means less weight of the vehicle is and less fuel consumption, thereby reducing harmful emissions into the atmosphere. Aluminium proves to be the most viable material for automobile due to a number of reasons:
Firstly, there is no dearth of feedstock and enough mining and processing facilities all over the world. It can be recycled easily and indefinitely, scrap aluminium recycling forming a large part of the industry. When a car is scrapped, aluminum is readily recycled with a high scrap value, providing both economic and environmental benefits.
Secondly, aluminium is anti-corrosive and can be kept in out of doors without damage. Aluminum resists corrosion by water and road salt without galvanizing, coating and painting and it is great for use both in cosmetic parts as well as in parts that are critical from engineering point of view. Smooth aluminum is highly reflective of heat and light. Its high reflectivity gives aluminum a cosmetic advantage that turns out to be a gifted quality for automobiles. Due to the soaring automobile price, consumers want their cars to retain their appearance and keep a high resale value for a long time which can be provided by aluminium.
Thirdly, it provides the same stiffness like steel with half the weight of steel. The interesting factor is that an aluminium vehicle can be made 20% larger in size than a steel vehicle of same weight. This lets automobile designers take liberty in design and overall size without adding extra weight. Lighter aluminum body cars have faster pickup and brake quicker than their heavier counterparts.
Finally, aluminium is already used extensively in architectural construction with proven efficiency and strength. Aluminum alloys will retain strength and flexibility and absorbs more crash energy. Aluminium is friendly to casting, stamping, forging, bending, extruding, cutting, drilling, punching etc. Aluminum does not strike sparks nor gets brittle under extreme cold and heat.
The use of aluminum in vehicles is increasing across all market segments and application types. According to the latest Ducker Worldwide growth report aluminum represents 7.8 percent of vehicle curb weight internationally. And the trend is expected to continue in the automotive sector in future. Automotive aluminum is gaining preference in vehicle engineering as the emphasis is shifting towards manufacturing more eco-friendly, fuel-efficient, stylish and lightweight cars with anti-aging properties. Other materials, such as magnesium, carbon fiber composites and injection molded plastics are other options in this regard. But they involve higher costs and magnesium is not an abundant metal. Aluminium is also costlier than steel and cast iron and so an aluminum car will be more expensive for a consumer. But, that will ultimately save a good amount of fuel cost and energy in the long run. Consumers will be “paid back” faster at the fuel pump if automakers opt to reduce vehicle weight through greater use of auto aluminum.