The countdown to Euro 7 brake systems compliance
It has been more than three years since the European Commission published its proposal for the Euro 7 emissions standard, outlining what it hopes will be the foundation for a cleaner automotive industry. The November 2022 statement laid out targets for the reduction of vehicle emissions beyond just the exhaust.
The most recent Euro 7 text states that particulate emissions from brake abrasion (PM10) must not exceed: 3mg per kilometre for light electric vehicles (Evs); 7mg/km for all other light vehicles; 5mg/km for light electric commercial vehicles; and 11mg/km for all other light commercial vehicles.
The challenge is to minimise particulate matter and ensure that the condition of the brake disc can be verified throughout the product life cycle.
These standards will apply from 29th November, 2026, for newly type-approved passenger cars and light commercial vehicles, and from 29th November, 2027, for all newly registered passenger cars.
Industry view
While OE components are heavily regulated, specific final requirements for the Independent Aftermarket (IAM) are still under discussion, leading to concerns about potential “two-tier” markets.
The UK’s Independent Automotive Aftermarket Federation (IAAF) has previously warned of significant testing burdens and costs for parts manufacturers, and compatibility issues which may force the installation of “friction couples” only. It also called for the mandate of OEM data sharing to support aftermarket compliance.
Meanwhile, aftermarket components manufacturer Otto Zimmerman, sees Euro 7 as “a great opportunity for innovation”.
“That is why we are already developing our own solutions for brake discs in combination with specially developed brake pads during the ongoing negotiations. In-house test benches are available to ensure compliance with future limit values,” the company said. “These have recently been supplemented by a particle test bench sourced specifically for this purpose.”
Material change on the horizon
In the past, most brakes were made of grey cast iron or cast steel. In order to reduce particulate matter, they are now coated with a chrome or molybdenum alloy. However, in view of the new Euro 7 standard, ceramic brake discs are increasingly coming into focus.
Carbon-ceramic brake discs, for example, are being used to reduce emissions in accordance with the new standard. This combination of materials emits up to 90 per cent less particulate matter. Regardless of which variant the manufacturer chooses, however, the thickness of the coating must be regularly checked in accordance with the upcoming emissions directive to ensure that the required values are met. Until now, the technical approach to this has been extremely complex and costly.
Laser-based wear marking
With this method, brake discs can be visually assessed at any time, without the need for sensors or removal. Swiss manufacturer Trotec Laser, shares how its solutions use a 100-watt picosecond laser for this purpose, which employs cold ablation to create markings with a depth of 90 µm ± 5 µm without subjecting the material to thermal stress. The cycle time depends on the project and line. For example, it is six seconds for a 3mm circle. The roughness (Rz) remains below 10 µm, guaranteeing high legibility even after thermal stress.
The key to meeting standards
For example, a European sports car manufacturer uses Trotec lasers to mark wear indicators on carbon-ceramic discs. The marking remains legible even after exposure to 600 °C and enables easy visual inspection during maintenance.“With our laser-based wear marking product solution, we enable not only OEMs and suppliers to comply with Euro 7, but also create real added value for their workshops and customers,” said Walter Bille, key account manager for the automotive sector at Trotec Laser Solutions.