As the regulations aiming to limit air pollution become stricter, the battle against non-exhaust emissions known to be harmful to human health and the environment is attracting more focus and extending worldwide.
EVs are equipped with a hybrid braking system combining regenerative and hydraulic braking to provide the same performance as traditional vehicles. Whenever the regenerative braking torque is insufficient to give the necessary deceleration rate, the hydraulic and electromechanical braking torque is applied. Thus, the recuperative braking of EVs reduces the need for brakes. As the brakes are not used as often, dust and rust will accumulate and impede their performance, so brake problems can arise from not using them enough. Due to the extra weight of EVs compared to ICEVs, more particulates are released through increased corrosion and friction on the braking system.
Grey cast iron brake rotors rust quickly, and excessive corrosion causes heavy damage to the rotor’s surface, which wears down severely, leading to mass loss, irregular vibration, and pedal pulsation when braking. Therefore, one of the most economical measures to effectively reduce particulate emissions (PM) is the application of ferritic nitrocarburizing. However, this approach is still insufficient to reach the desired objectives or address the challenges electric vehicles present.
The new generation of FNC rotors developed by Nitrex R&D is not limited to FNC; the focus has shifted towards using Smart ONC®. This exclusive and promising process provides rotors with superior corrosion resistance, allowing them to withstand salt spray exposure for up to 120 hours without any corrosion. This is a tremendous improvement over FNC-treated rotors, which only last for less than 20 hours in the same environment.
This paper and presentation will follow up on our contribution from 2022 and present Nitrex’s latest findings and developments.