INFLUENCE OF FRICTION MATERIAL PROPERTIES ON THERMAL DISC CRACK BEHAVIOR IN BRAKE SYSTEMS

This work investigates how the properties of the friction material that acts against the brake disc may influence the thermal crack evolution of a disc material, when submitted to two distinct brake conditions. Three different friction materials were tested on a dynamometer under conditions that simulate real vehicle situations, the first one reproducing usual conditions of passenger car operation and the second one reproducing a normal commercial vehicle usage. The thermal crack growth rate was measured in both procedures to establish the response of the systems investigated. When different friction materials are evaluated in the same test procedure, the lowest crack growth rate can be obtained if friction materials are produced with higher values of compressibility and thermal transmission and lower values of resilience, cross breaking and internal shear strength.