A Comparison of Methods for Characterizing Brake Pad Surfaces

The brake industry is currently driven towards lighter, corrosion resistant and more eco-friendly brake systems in order to meet the current health and environmental demands and megatrends of electrification and autonomous driving. While trying to meet these new demands, there is no room for compromising the brake systems friction and wear performance. Understanding the friction interface of the brake system is therefore key to being able to meet these often-contradicting demands. The contact situation in the friction interface is generally described by a friction layer that is formed during the braking process. The friction layer makes up the real contact area between the static brake pad and the rotating brake disc. It is only a fraction of the size of the apparent pad area and is present in the form of so-called contact plateaux. This study compares the method of image segmentation that utilizes a light microscope to capture the contact plateaux of a brake pad surface with a different method that uses a focused ion beam for the detection of the contact plateaux.