Until now, brake discs have mainly been of two types. Conventional, made from cast iron castings, are relatively cheap, but they wear out quickly, generate a lot of dust and quickly lose their braking properties under heavy loads and heating.
The latter is not a problem for ceramic discs, which wear out slowly and withstand incomparably higher loads. But their price is shocking and often exceeds the price of a new compact car.
New from Porsche
However, Porsche is now offering an innovative solution that sits somewhere between classic and ceramic brakes. In their design, called PSCB, the discs are coated with a thin layer of tungsten carbide - only about one tenth of a millimeter.
This procedure is performed by a special technique - at very high temperatures and under high pressure (particles of the substance hit the metal of the disk at a speed exceeding the speed of sound). This ensures that the cover is firmly fixed.
Feature of tungsten carbide
Tungsten carbide is an inorganic carbon compound that has been known for a long time and, due to its extraordinary hardness, is widely used in the manufacture of drills for drilling machines, as well as in armor-piercing shells and cartridges.
Sealed and metal-like, this compound can withstand very high temperatures - up to 2600 degrees Celsius (after which it decomposes, but does not melt).
Difference between tungsten and conventional brakes
The difference with ordinary discs is visible to the naked eye: tungsten is almost mirror-like. And since brake soot emissions have been reduced by 90% compared to conventional ones, Porsche has specially fitted white brake calipers to highlight this fact.
Even though the tungsten carbide layer is very thin, it lasts a long time - 30% more than usual, Porsche explains. At the same time, the substance does not lose its braking properties when heated and does not heat up as much as conventional iron discs. It is completely resistant to rust, which is usually found on rims, especially if the car is not used for several days.
Feature of using tungsten brakes
The effect of a new disc cannot fully manifest itself with conventional pads, simply because the surface is too smooth. This is why Porsche has developed special pads for it, which have a kind of miniature anchors on the surface.
In some ways, tungsten discs outperform even ceramic discs, which are not as effective until the optimum temperature is reached. In addition, PSCBs cost only a third of the cost of ceramic. They are much more expensive than ordinary ones, but they last a third longer, so this compensates somewhat.
These brakes are mainly used in sports cars (Porsche fitted them as standard on the Cayenne Turbo), but also in vehicles that are often used for towing, for example.