The Fraunhofer Institute for Manufacturing Technology and Advanced Materials (IFAM) reports that it is collaborating with brake pad and friction solutions specialist SBS Friction A/S, Svendborg, Denmark, and the Danish Technological Institute, to develop an iron-based sintered brake pad for motorcycles as part of the ‘Green Pad’ project. Supported by the Innovation Fund Denmark, the project seeks to create an environmentally friendly alternative to established surfacing materials.
The aim of the research project is to develop copper- and nickel-free sintered brake pads with tribological properties equivalent to those of conventional metal brake pads. Initial tests have shown that the new iron-based developments are achieving promising results, which have been demonstrated both in the laboratory and in use in a motorcycle.
Sintered brake pads are superior to organically bonded pads due to their high temperature resistance, as well as their properties with regard to wear, abrasion and coefficient of friction, and are used for high-performance brakes, for example in rail transport or in motorcycles and bicycles.
Currently, there are said to be no environmentally friendly metal alternatives. However, the institute states that there are clear commercial, economic and environmental reasons for abolishing the use of copper and nickel in production, and these driving forces will become stronger as stricter legislation is implemented.
It is for this reason that Fraunhofer IFAM believes new solutions for metal sintered brake pads are urgently needed. Additionally, it explains that new solutions for metal brake pads are also required for environmental reasons because brakes for high-performance applications are generally copper-based, which is considered to be highly toxic to aquatic species.
The institute states that from 2021, brake pads with a copper content of more than 5% will no longer be allowed to be sold in the US states of Washington and California, and by 2025, brake pads must be almost completely copper-free, with a maximum content of 0.5%
Considering the motorcycle market as a whole, the use of copper- and nickel-free products could potentially reduce copper emissions by 600 tonnes per year. This is equivalent to approximately 25% of the emissions from copper brake wear throughout Europe. For nickel, the potential savings are 160 tons per year. These effects become even greater when additional target segments such as racing cars, scooters, high-quality mountain bikes, ATVs and industrial machinery are taken into account.
Within the Green Pad project, Fraunhofer IFAM explains that it is applying expertise to solve tribological material problems. In addition to tribological tests, material developments for all tribological applications and the optimisation and design of friction pairings, tribological damage cases are also assessed at the institute.