Effects of Disk Material Selection on Disk Brake Rotor Configuration

Due to the recent requirements of FMVSS-121 for improvements in heavy vehicle braking capabilities, the high torque caliper type disk brake is emerging as the “superior brake”. Caliper disk brakes not only possess high linear torque capabilities but also excellent directional stability wheel to wheel. However, the high torque capabilities result in high energy input to the disk. This high energy produces premature failure in the traditionally used cast iron ventilated disk in the form of “temperature induced cracking”. This paper will discuss the thermal mechanisms that produce “disk cracking” and how disk material selection affects the disk configuration.