Cast iron is a well-known material used since years for production of brake discs and drums. It offers good machinability, wear resistance, damping properties and low cost. There are different types of grey cast iron used for production of brake discs. Usually the carbon content [C%] varies between 3,2 4,0 C%. Standard Test Method for Evaluating the Microstructure of Graphite in Iron Castings ASTM A247 is mainly used for material evaluation. It may happen that two materials that achieve similar rating according to ASTM A247, do have significant differences in terms of wear resistance. The brake industry looks for ways to limit brake wear not only because customer satisfaction (dust on wheels, replacement of worn parts) but also due to increasing focus on particle emissions. It is important to identify objective parameters that will allow distinguishing iron castings to be distinguished in terms of wear performance.

Grabiec Tomasz, Ford Werke GmbH, Chassis Engineering, Germany; Adamiec Janusz, Silesian University of Technology, Faculty of Materials Engineering and Metallurgy, Poland