Starting in the late '90s, a new and innovative brake disk technology entered the high performance passenger car market. Approx. 2 years later, small volume production of carbon-ceramic brake disks started. In the past ten years the number of cars equipped with the new generation of ceramic matrix composite (CMC) brake disks has continuously increased, with main usage in low volume, high horse power applications.
The goal of this paper is to give an overview of the system specific boundary conditions as well as today's and tomorrow's targets and aspects of friction material development used in CMC-disk based brake systems.
Starting with a description of the system component properties, a comparison of typical CMC vs. standard gray cast iron disk (GCI) applications will be made. The impact of the component properties, especially the disk as friction counterpart to the pad, will be shown by comparing industry standard test scenarios.
One described system boundary will be the thermal load to the brake pad. Based on a selected sample application and by means of both chemical- and physical measurement methods, both the reversible and irreversible effects of thermal load to the brake pad will be shown and discussed.
Finally, current solutions and future development needs will be proposed that allow for more emphasis on one of the different engineering goals while simultaneously keeping the needed balance.