Aluminum-Alloy Brake Rotor Designed for 200,000 Miles

NEW YORK – A New York researcher and engineers with a Michigan-based company are developing an aluminum-alloy brake rotor that could replace today's cast-iron versions at far less cost than the ceramic parts now available only in high-priced sports cars and racing vehicles.

Nikhil Gupta, a professor at the Polytechnic Institute of New York University, tells WardsAuto that a prototype of the new rotor will be ready in about a year. Gupta's team, consisting of three graduate students and one undergraduate, have spent two years researching the dynamic properties of the composites that will be used.

The researchers are working in collaboration with REL of Calumet, MI, which specializes in developing lightweight composite materials for motorcycle brakes, lightweight survivability materials and high-temperature insulation materials.

REL received a $150,000 small-business innovation research grant from the National Science Foundation to develop the new rotor. The company has retained Gupta's composites materials and mechanics lab to develop a rotor for automotive applications.

The rotor market accounts for about $10 billion in annual sales.

Gupta says the next-generation rotor uses glass fibers and ceramic particles in the aluminum matrix. There are more glass fibers near the surface of the rotor and fewer toward the hub. The fibers are a mile (1.6 km) or more in length. In the laboratory, the fibers, which are 15 microns in diameter – one-sixth the width of a human hair – are cut into pieces a few inches in length.

The researcher contends the resulting rotors will be superior in thermal resistance, yielding a fourfold improvement in heat conductivity. Corrosion resistance is superior to steel and iron rotors and the new brake components won't be noisier than today's parts.

Gupta estimates the production rotor will weigh 60% less than cast-iron rotors. What's more, the greater wear and friction resistance of the aluminum rotor will achieve 200,000 miles (320,000 km) of service in a midsize car.

He says the team expects over the lifetime of the car, the new rotor will be cost-competitive with the cast-iron rotors that can cost automotive OEMs as little as $12 each from Chinese suppliers.

The initial cost certainly will be higher than cast-iron rotors, but the new aluminum/glass fiber design will be far less expensive than ceramic versions which can command up to 1,000 times the cost of conventional rotors.