Expensive, but forever: ceramic brake discs

A spacecraft entering the Earth's atmosphere experiences intense air resistance. That is why space capsules and shuttles have thermal protection that can withstand high temperatures. These ceramic tiles have found their way into the automotive industry in the form of brake discs. After all, the brake system is most affected by high temperatures due to friction.

What are ceramic brakes?

Hearing the word " ceramics ”, you might think of ceramics. Really , ceramic components are in high demand in the industry. Their especially strong insulating effect against power surges and heat makes them a suitable material for extreme environments .

The brakes use a special ceramic material: The composite of carbon fiber and silicon carbide is an ideal blend for absorbing high frictional energy.

Therefore, ceramic brakes are equipped with one or more components made of this material, which has both advantages and disadvantages .

Ideal against fading effect

The car's brakes work by friction. . The stationary carrier with lining is pressed against the rotating element, creating frictional energy, thereby reducing the energy of motion. Friction generates excess heat, which can be a problem.
When the friction temperature approaches the melting point of the rotating element, i.e. the disk or drum , the braking effect is reduced . In already obsolete brake drums, this sometimes led to complete failure.

This is where ceramic brake discs provide the solution. . Their construction material has a very high melting point that is never reached even under the most difficult driving conditions. Carbon ceramic brake discs are not only light and safe ; with normal use, they practically last forever. Term service up to 350 km is the standard for these elements.

Due to material properties, gray cast steel brake discs are susceptible to corrosion. . These modules rely heavily on their self-cleaning effect under normal driving conditions.

As a non-metallic material, carbon-ceramic composite is completely immune to salt and corrosion. . The absence of rust flash and the associated abrasion of the rust layer during braking is a key element in the wear resistance of carbon-ceramic brake discs.

Main problem: heat dissipation

The heat generated by the carbon-ceramic brake discs is no longer absorbed and therefore the surrounding components are exposed to the temperature . As a result of heat generation, brake hoses and sensor cables need to be protected with ceramic fiber insulation.

Limiting temperatures have been measured in these modules up to 1600°C. Ceramic brake discs require matching brake pads. Therefore, replacing steel brake discs with ceramic brake discs is more of a challenge than is commonly believed.

No haggling - for now

Gray cast steel brake discs are injection molded and then ground to size . When something goes wrong, the brake disc is simply melted down and recast. There is practically no material loss in this production process.

Defective carbon-ceramic brake discs, on the other hand, cannot be melted down. . They can be crushed and used as an additive in the construction industry. However, the cheap recycling of scrap and residual material, common in metalworking, does not apply here. .

This is one of the reasons why carbon ceramic brake discs are very expensive . For comparison: a ceramic brake system can easily cost up to €10 (±£000) . It doesn't pay off even for luxury family cars. So the default setting reserved for limousines, sports cars, professional racing cars, CIT vans и armored vehicles .

However, electric mobility may drive general adoption . In addition to excellent braking performance and exceptional durability, carbon ceramic brakes are very light . In an electric car, every ounce saved immediately affects its range. Therefore, carbon-ceramic brake discs can contribute to weight savings. However, this is still a long way off.

Beneficial uses of ceramics

Nevertheless, use ceramic components in standard cars is justified . Instead of replacing cast steel wheels with carbon-ceramic components, an adequate alternative is the installation of ceramic brake pads.

Ceramic brake pads are available from well-known manufacturers as an accessory . They are installed in exactly the same way as traditional brake pads. Their use gives several advantages:

– increased wear resistance - less abrasion – noise reduction – better grip with a wet brake disc

Braking performance Ceramic brake pads can be compared to traditional pads. Have in mind if your car is equipped with beautiful rims, you are doing yourself a favor by using ceramic brake pads . The dreaded abrasion tends to leave a stubborn dust layer that is hard to get rid of. Ceramic brake pads cause significantly less abrasion.

More surprising cheap brake kits with ceramic brake linings. Branded manufacturers offer prices for this solution that hardly exceed the prices of traditional brake kits: the ATE brake kit, including brake disc, linings and additional parts, costs from approx. €130 (± £115) .

This is by no means excessive for an OEM quality product from a reputable supplier. . These low prices make it worth choosing this feature at your next brake maintenance.

Always choose innovation

The development of brake discs goes beyond the use of ceramics. The latest development is hybrid drives: traditional gray cast steel brake disc riveted to aluminum holder . Where superior wear and heat dissipation properties are required, hybrid brake discs provide full performance.

The word "mass" is here: simple single brake discs are almost never used these days . Dual ventilated brake discs are now standard on the front axle.
Unfortunately, many benefits offered by these innovative components such as improved heat dissipation and performance , go hand in hand with the added mass.

However, this can be offset in other details: where heavy cast steel adds to the vehicle's overall weight, the hybrid brake discs feature lightweight aluminum . The connecting part between the brake ring and the wheel hub is made of light metal in high performance brake discs .

Of course, this is only a small contribution to weight reduction. . However, since brake discs are a critical moving mass, any reduction in weight is welcome. The lightweight brake disc causes less imbalance while sparing the complex steer axle mechanism.

No difference in quality the strength of aluminum in the right alloy can now be compared with steel .

Why isn't the entire rim aluminum?

Manufacture of the entire brake disc from aluminum impossible for two reasons:

– low melting point - not strong enough

aluminum melts at 600 ° C . Standard braking maneuver easily leads to temperatures over 1000 ° C , and so the light metal will fail after a few braking attempts.

And what's more: aluminum is subject to abrasion. Wear is unacceptable even with careful braking. Thus, the use of light metal as the basis for the brake ring is the ultimate application of this material in the brake system.