Materials used for Automotive Body Structure
The choice of materials for a vehicle is the first and most important factor for automotive design. There is a variety of materials that can be used in the automotive body and chassis, but the purpose of design is the main challenge here.
The most important criteria that a material should meet are lightweight, economic effectiveness, safety, recyclability and life cycle considerations. Some of these criteria are the result of legislation and regulation and some are the requirements of the customers.
The car industry uses a tremendous number of materials to build cars, including iron, aluminum, plastic steel, glass, rubber, petroleum products, copper, steel and others. These parts are used to create everything from those small things we don’t think about, such as dashboard needles and wiring, to the big stuff, such as the engine block or the transmission gears.
These materials have evolved greatly over the decades, becoming more sophisticated, better built, and safer. They’ve changed as new automotive manufacturing technologies have emerged over the years, and they’re used in increasingly innovative ways.
New Lighter Materials
For the past four or five decades, the basic shape and design of production cars haven’t really changed. We still mostly have front-engine layouts built with unibody chassis. What has changed are the materials used in car construction. We have seen significant reductions in the weight of cars with new construction materials like high-strength steels and aluminum. Unfortunately, all of these savings have been counteracted by stouter, bigger car designs, as well as heavy new safety features. Advanced materials are essential for boosting the fuel economy of modern automobiles while maintaining safety and performance. Because it takes less energy to accelerate a lighter object than a heavier one, lightweight materials offer great potential for increasing vehicle efficiency. A 10% reduction in vehicle weight can result in a 6%-8% fuel economy improvement. Replacing cast iron and traditional steel components with lightweight materials such as high-strength steel, magnesium (Mg) alloys, aluminum (Al) alloys, carbon fiber, and polymer composites can directly reduce the weight of a vehicle’s body and chassis by up to 50 percent and therefore reduce a vehicle’s fuel consumption. Using lightweight components and high-efficiency engines enabled by advanced materials in one quarter of the U.S. fleet could save more than 5 billion gallons of fuel annually by 2030. By using lightweight structural materials, cars can carry additional advanced emission control systems, safety devices, and integrated electronic systems without increasing the overall weight of the vehicle. While any vehicle can use lightweight materials, they are especially important for hybrid electric, plug-in hybrid electric, and electric vehicles. Using lightweight materials in these vehicles can offset the weight of power systems such as batteries and electric motors, improving the efficiency and increasing their all-electric range. Alternatively, the use of lightweight materials could result in needing a smaller and lower cost battery while keeping the all-electric range of plug-in vehicles constant.
Of course, nobody can predict the future direction of vehicles, but these advances reaffirm the key role plastics play in today’s cars, making them more fuel efficient, safer, more fun to drive, and reducing their environmental footprint. It’s likely that plastics will continue to play that role for the foreseeable future.