Finding the Right Lightweight Metal for Your Powertrains and Transmissions

Advanced materials boost the fuel economy of vehicles.

Replacing traditional steel components like drivetrains, suspensions, and transmission gears with lightweight materials such as high-strength steel, magnesium alloys, aluminum 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 lighter vehicle parts can offset the weight of batteries and electric motors, as well as the powertrain system, engine components, transmissions, driveshafts, differentia gears, and axles.

A Tech Briefs article reviews the pros and cons of the advanced materials. Learn which advanced metal is the correct choice for your vehicle part, from powertrains to universal joints.

  • Aluminum: Manufacturers currently turn to aluminum to manufacture vehicle hoods, panels, and powertrain components like engine cylinders, drive shafts and differentials. The Ford Escape, shown in the article, features machined-aluminum wheels.

The lightweight metal, however, is increasingly being used on hoods, trunk lids, and doors. See how aluminum has the potential to reduce vehicle weight by up to 60 percent.

  • Titanium: This high-temperature metal reduces weight in powertrain systems by up to 55 percent. Titanium is also supporting the latest transmission valves, springs, suspensions, wheels, differential gears, and gearbox housings.

Titanium can take the heat, but is the cost too high? The Tech Briefs article reveals the benefits and drawbacks of the advanced material.

  • Magnesium: With the lowest density of all structural metals, magnesium alloys have the potential to reduce component by weight up to 70 percent. Magnesium is presently used in castings for powertrains or subassembly closures.

Magnesium has high stiffness and strength, but there are challenges related to ductility, joining, repair, recycling, and corrosion.

  • Carbon Fiber Composites: Despite being half the weight of steel, carbon fiber composites are four times stronger and have the potential to reduce vehicle weight by up to 70 percent. Highly complex shapes can be made from carbon fiber, but there are production costs.
  • Advanced High-Strength Steel: Stronger and more ductile than typical steel, this material could reduce component weight by up to 25 percent, particularly in strength-limited designs such as pillars and door rings. But should you use the high-strength steel over aluminum?

Computational materials science should bring advanced materials into the market at a much faster rate than in the past. Researchers will also increasingly employ computational approaches to create vehicle designs that maximize the potential of these materials.

The U.S. Department of Energy’s Vehicle Technologies Office (VTO) works with the Lightweight Materials National Laboratory Consortium (LightMAT), a network of 10 national laboratories, to develop advanced materials that help boost the fuel economy of modern vehicles, while maintaining safety and performance.

By using lightweight structural materials, vehicles can carry additional advanced emission control systems, safety devices, and integrated electronic systems without increasing the overall weight of the vehicle.

The most effective way of reducing the overall weight of a vehicle is to select the right structural material for the right application. Each lightweight structural material has strengths and weaknesses.

Use this Tech Briefs article to help you make your decisions.

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