ROCATRON long-term corrosion protection (LCP) was developed for brake discs and use in electric vehicles. With the aim to protect brake discs for much longer use in vehicle than today.
The corrosion protection used in Europe today is only a so called short term protection. This means that after a relatively short period of use, the brake disc is more or less unprotected.
Depending on the area of application, there are other types of corrosion protection. While the above-mentioned types of corrosion protection are almost exclusively used in Europe, nitriding (known as FNC) of brake discs is used in other continents.
Depending on the area of application in Europe, types of corrosion protection are used that allow the use of Low Met brake pads and NAO brake pads. In some areas the brake discs are nitrided after final processing. Due to the resulting distortion of the brake disc, this type of coating can only be used with NAO brake pads. In some areas the brake discs are nitrided after final processing. Due to the resulting distortion of the brake disc, this type of coating can only be used with NAO brake pads.
Due to the electric drive and the associated recuperation, the friction brakes are only used very little. The majority of braking (up to 95%) is done electrically. This extends the time the brake disc stays in the vehicle, which in turn means an increased impact on the environment. This inevitably creates a need for a corrosion protection process that meets the new requirements.
The ROCATRON long-term corrosion protection (LCP) with processing of the clean surfaces after coating allows both low met and NAO brake pads to be used.
The long-term corrosion protection developed by ROCATRON covers all surfaces of the brake disc. For this purpose, an alloy is sprayed on, which then diffuses into the cast material via heat treatment. The brake disc is getting a distortion during heat treatment. Distortion will be eliminated by machining the friction surfaces and the contact surface so that the brake disc returns to its original geometry.
Long-term corrosion protection has the following advantages.
| Problem | Impact | Solution Approach |
|---|---|---|
| Significantly longer time in the vehicle | Corrosion, especially on non-active surfaces | Secured |
| Corrosion build-up on friction surfaces during driving | Rust formation and thus a direct impact on braking and comfort behavior | No more control system required |
| Corrosion build-up on friction surfaces when stationary | Rust formation and thus a direct impact on braking and comfort behavior | Secured |
| Optical Appearance | Unacceptable appearance due to rusting | Secured |
| Wear Behaviour | Emissions level too high | Reduction |
The development showed that the ROCATRON long-term corrosion protection (LCP) is a so-called plug and play variant. This means that the operational properties of the comparable brake disc are not negatively affected.
As long as the basic disc is homologated, no further measures are required for road traffic approval.
