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.
Research and development into lightweight materials is essential for lowering their cost, increasing their ability to be recycled, enabling their integration into vehicles, and maximizing their fuel economy benefits.
The Vehicle Technologies Office (VTO) works to improve these materials in four ways:
- Increasing understanding of the materials themselves through modeling and computational materials science
- Improving their properties (such as strength, stiffness, and ductility)
- Improving their manufacturing (material cost, production rate, or yield)
- Developing alloys of advanced materials
In the short term, replacing heavy steel components with materials such as high-strength steel, aluminum, or glass fiber-reinforced polymer composites can decrease component weight by 10-60 percent. Scientists already understand the properties of these materials and the associated manufacturing processes. Researchers are working to lower their cost and improve the processes for joining, modeling, and recycling these materials.
Learn more about the research VTO supports in short-term applied research in advanced high-strength steel and aluminum.
In the longer term, advanced materials such as magnesium and carbon fiber reinforced composites could reduce the weight of some components by 50-75 percent. The Office is working to increase our knowledge of these materials' chemical and physical properties and reduce their cost.
Learn more about the research VTO supports in long-term applied research in magnesium and carbon fiber.
Further developing advanced materials requires increasing our understanding of their composition and morphology. While past research used physical experiments to better understand conventional steel and aluminum, computational materials science can speed up the process by simulating experiments. Computational materials science should bring advanced materials like magnesium into the market much faster than materials in the past. Researchers can also use computational approaches to create vehicle designs that maximize these materials' potential.
To improve these tools, VTO works with the Materials Genome Initiative, an interagency effort that supports reducing the time needed to develop advanced materials and structures through integrated computation, experimentation, and data. Work supported by VTO has developed computational tools that enabled improvements in joining methods, corrosion prevention, and predictive models.
Partnerships, Goals and Results
This research and development focuses on achieving the following goal: by 2015, to validate the ability to reduce the weight of a passenger vehicle body and chassis system by 50% compared to a 2002 vehicle. This reduction needs to be cost-effective and the materials need to be recyclable as well.
The results of these research and development activities are described annually at the Annual Merit Review and Peer Evaluation Meeting and in the annual Progress Report. In addition, the Materials subprogram hosted a Lightweight and Propulsion Materials workshop in March 2011 in Dearborn, Michigan to understand industry's needs and technology gaps. These reports serve as a benchmark of current state-of-the-art technologies as well as technical goals in these areas: Light-Duty Vehicles Technical Requirements and Gaps for Lightweight and Propulsion Materials and Trucks and Heavy-Duty Vehicles Technical Requirements and Gaps for Lightweight and Propulsion Materials.