Researchers at the Polytechnic Institute of New York University (NYU-Poly) and Michigan-based REL, Inc. are creating a next-generation aluminum composite brake rotor potentially weighing 60 percent less than today’s cast iron rotors with triple the life expectancy. The fiber-reinforced, metal matrix composite (MMC) brake rotor will shave approximately 30 pounds from a mid-size sedan.

REL received a $150,000 Phase I Small Business Innovation Research (SBIR) grant from the National Science Foundation to develop the initial product design, material, and manufacturing process. The company tapped the expertise of NYU-Poly Mechanical and Aerospace Engineering Associate Professor Nikhil Gupta and his Composites Materials and Mechanics Lab to develop the technology for automotive application.

Gupta and REL are developing a one-piece brake rotor tailored to meet the extreme and variable temperature and loading conditions. Most of today's brake rotors are made of cast iron, which offers strength but at a cost of weight. Iron also doesn’t adapt well to the demands placed on different sections of the rotor. A brake rotor has three functional zones, each of which requires a material with distinct strain and thermal properties to function optimally. Temperature and pressure changes across the rotor surface are a major cause of wear, warp, and brake failure.

The team will replace the traditional rotor material with a high-temperature aluminum alloy reinforced with functionally graded ceramic particles and fibers to create a lightweight but extremely durable material that can be customized to best serve each section of the rotor.

"These functionally graded materials allow us to create the optimal composition for each part of the rotor," Gupta explained. "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. Together, this should boost rotor life significantly, reducing warranty and replacement costs, and the weight savings will improve the vehicle’s fuel efficiency.”

In addition to the automotive market, the composite rotors may benefit military fleets, where up-armored vehicles operate at weights well above their design capacity. 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.