April 13, 2012
Researchers in Brooklyn and Michigan are collaborating on a next-generation aluminum composite brake rotor potentially weighing 50 to 60 percent less than today’s cast iron rotors, with triple the life expectancy. REL, Inc., a developer of transportation and aerospace components, received a $150,000 Phase I Small Business Innovation Research Grant from the National Science Foundation to develop the initial product design, material, and manufacturing process. The company then tapped NYU-Poly mechanical and aerospace engineering associate professor Nikhil Gupta and his Composites Materials and Mechanics Lab to develop the technology for automotive application.
The collaboration will result in a prototype rotor that may revolutionize a market valued at $10 billion annually.
Due to expense, today’s composite brakes have been reserved for motorcycles, race cars, and high-performance sports cars, but this new, fiber- and particle-reinforced metal matrix composite (MMC) brake rotor aims to be inexpensive enough to appeal to the manufacturers of mass-market cars. It will be easier to manufacture, and the fiber reinforcements will provide longer life span.
The researchers also estimate that their composite rotor will shave approximately 30 pounds from a mid-size sedan —a significant advantage in an industry facing a potential requirement to double its fuel economy by 2025. Gupta and the team at REL expect to complete a functional rotor prototype within 12 months.
To make their composite brake rotors superior in strength and performance to cast iron ones, the team designed a functional grading technology. This means that the ratio of aluminum to ceramic reinforcements will vary throughout the rotor, based on the forces exerted on particular areas. For example, the interface where the brake pad clamps down on the rotor becomes very hot from friction. Since ceramic can better withstand heat, the composite will contain more ceramic in that area compared to a less-taxed area, such as the rotor’s center.
“The hybrid material allows us to provide reinforcement where additional strength is needed, increase high-temperature performance, and minimize stress at the interfaces between the zones,” Gupta says. “Together, this should boost rotor life significantly, and the weight savings will improve the vehicle’s fuel efficiency.”
In addition to the automotive market, the composite rotors may benefit military fleets. While the development of lightweight armor remains a long-term goal for the military, any weight savings on the vehicles themselves will immediately improve fleet efficiency, which can be critical to mission success where fuel delivery is difficult.