First developed by SAB WABCO in the UK in the late 1980’s then manufactured by SGL Carbon of Germany for the Porsche 911 from 2001, carbon ceramic automobile brake applications have grown steadily so that now most self respecting supercars and high performance cars have them as standard, or as an option.
The earlier generation carbon-carbon brakes from Dunlop Aerospace were first seen on the ubiquitous Concorde supersonic airliner in 1976, then introduced by Brabham, with Gordon Murray as Technical Director, into Formula 1 in 1979.
Carbon ceramic brakes differ in their chemical composition and fundamentally in their braking performance as they do not need to be at 600ºC before they start working as an effective brake. They are also extremely light (approximately 25% of the weight of a cast iron installation) and perhaps more importantly, can operate at much higher temperatures without damage to the brake, though the pad and surrounding non-metallic bodywork need to be well engineered to resist 1000ºC disc surface temperatures.
Ceramic brakes can store large quantities of heat so static and dynamic cooling is very important.
Like many new innovations, carbon ceramic brakes have pitfalls. They need to be well designed for the application – over-designed brakes can lose the benefit of weight saving and not work properly, as there is definitely an important “window” for optimal operation. They also need to be matched to the correct pads to minimise noise, vibration and harshness (NVH). Interestingly the early Porsche PCCB brakes had quite a loud “chirp” when the car came to a halt, gently informing the drivers around them that this machine was equipped with the best and most expensive brakes available! At around €6000 a car set, they were and still are the ultimate in “one-upmanship”.
On the down-side heavy use could lead to overheating and sudden catastrophic failure. One particular exclusive supercar with ceramic brakes had a significant number of accidents, with some of those being blamed on brakes.
Ceramic brakes from one manufacturer had a thin wear layer which if damaged would require very expensive disc replacement. Heavy handed mechanics have also been known to drop these precious rotors only to see them chip and crack.
Quality control problems from another manufacturer would sometimes lead to differential frictional properties and under braking, transforming a performance car into an uncontrollable beast.
On the economic front there are deterrents such as high manufacturing costs, high energy consumption during manufacture and quality control problems.
However, a well designed carbon ceramic setup can provide stunning, secure braking with low fade, shorter stopping distances, better handling as a result of the reduced unsprung weight and reduced gyroscopic effect of the high speed rotors, whilst providing improvements to fuel economy due to the 20-30kg reduction in weight of the car. They are a revelation.
The future for automotive ceramic brakes lies in improved material properties, for both the disc and the pad, better manufacturing technology to significantly lower system costs while also improving product quality, system reliability and application engineering. More world scale manufacturers are expected to enter the market, currently dominated by the alliance of Brembo (Italy) and SGL (Germany).
Carbon Ceramics Ltd is staffed by engineers and scientists who were in at the beginning of the carbon ceramics revolution in the late 80’s. Together we intend to be at the forefront of the next technological advances, both technical and commercial, for this unique, lightweight, high performance material.