Ceramic-containing brake pads and rotors first began to appear as high-tech solutions for F1 and other auto and motorcycle racing applications and more recently have been appearing in commercial markets as high performance braking systems in the premium sedan and truck markets. While this technology is slowly making its way into mass-market vehicles, R&D work continues on perfecting such braking systems, and the latest news is that a team of researchers from Polytechnic Institute of New York University and Michigan-based REL Inc. say they have created a next-generation aluminum-ceramic composite brake rotor that may cut rotor weight 60 percent (compared to cast iron rotors). The team also says the new rotor’s functionally graded design could triple the lifespan of traditional rotors.
Looking at a market worth billions of dollars, REL Inc. applied for and received a $150,000 Phase I SBIR grant from the NSF to develop the initial product design, material and manufacturing process. REL had already established itself as a manufacturer of mixed matrix components for the auto and aerospace industry. The company recruited the expertise of NYU-Poly’s Nikhil Gupta, an associate professor at the school. Gupta leads the school’s Composite Materials and Mechanics Lab.
While strong, the heavy cast iron rotors apparently are a uniform material, which, according to Gupta and REL, contributes to warpage and wear because of nonuniform temperatures and pressure strains across the surface of the rotor. Instead, they say the optimal brake rotor needs to be designed with three functional regions, where each region is matched to a material with distinct strain and thermal properties.
To accomplish this region-based design, the team begins with a high-temperature aluminum alloy and reinforces it with functionally graded ceramic particles and fibers that impart unique characteristics to each section of the rotor.
Gupta explains in a news release, “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.”
Gupta and REL claim their one-piece design will be easier to manufacture than current ceramic and ceramic-composite braking systems and be able to penetrate into the $10 billion market. Their pitch to automakers is that their new rotors will last longer and slash approximately 30 pounds from a mid-size sedan.
“As auto companies strive to meet increasingly high efficiency and low emissions targets, there’s a tremendous business opportunity in creating novel lightweight components which reduce overall vehicle weight and increase vehicle performance,” says Adam Loukus, vice president of REL.
Gupta has also conducted research into the creation of polymer-based functionally graded components made by dispersing according to their wall thickness hollow glass microballons in a polymeric matrix.