In pursuit of lower vehicle weight to reduce emissions and improve fuel efficiency, Magna International Inc., in cooperation with Ford Motor Company, developed a prototype carbon fiber composite subframe which reduces mass by 34% compared to making a stamped steel equivalent. The subframe is a key part of a vehicle’s structure, typically providing a place to attach the engine and wheels while also contributing rigidity and crash management.
By replacing 45 steel parts with two molded and four metallic parts, the prototype subframe achieves an 87% reduction in the number of parts. The moldings are joined by adhesive bonding and structural rivets.
The carbon fiber subframe is the result of a research and development project between Magna and Ford to investigate potential mass-reduction benefits and technical challenges of using carbon fiber-reinforced composites in chassis applications. This is part of a larger effort by Ford to explore different design strategies for light chassis development, including magnesium subframes, carbon fiber subframes, aluminum cross-members and lightweight coil springs.
When we are able to work in close partnership with a customer at the beginning of their design and engineering processes, it’s an opportunity to bring our full Magna capabilities to bear. We are able to take a clean-sheet approach with design, materials and processing, collaborate with the customer and within our product groups, and deliver a solution with the potential to really move the needle in terms of aggressive lightweighting without sacrificing styling or performance.—Grahame Burrow, President of Magna Exteriors
Magna’s engineering team—an intra-company collaborative effort between the body & chassis and exteriors product groups—combined its full-vehicle knowledge on the design, materials and processing to address the challenge of reducing weight using composite materials and manufacturing processes.
The design has passed all performance requirements based on computer-aided engineering (CAE) analyses. The prototype subframes are now being produced by Magna for component and vehicle-level testing at Ford.
Collaboration is the key to success in designing lightweight components that can give our customers fuel economy improvements without compromising ride and handling, durability or safety. We must continue to work hard to achieve these lightweight solutions at the most affordable costs. Magna and Ford working together on this carbon fiber composite subframe is a great example of collaboration on advanced materials.—Mike Whitens, Director of Vehicle Enterprise Systems within Ford Research and Advanced Engineering
The testing phase will evaluate corrosion, stone chipping and bolt load retention, which aren’t currently measured by CAE. The project team will also develop a recommended design, manufacturing and assembly process with the experience gained during the prototype build and subsequent testing.
Magna has been pioneering the use of lightweight materials for a number of years, noted Burrow. The company launched a carbon fiber hood for the Cadillac CTS/ATS-V series, followed by a carbon fiber grille opening reinforcement for the Mustang Shelby Cobra GT500.