Thermophysical Properties of Automotive Brake Disk Materials

The temperature distribution, the thermal deformation, and the thermal stress of automotive brake disks have quite close relations with car safety; therefore, much research in this field has been performed. However, successful and satisfactory results have not been obtained because the temperature-dependent thermophysical properties of brake disk materials are not sufficiently known. In this study, the thermal diffusivity and the specific heat capacity of three kinds of iron series brake disk materials, FC250, FC170, and FCD50, and two kinds of aluminum series brake disk materials, Al MMC and A356, were measured in the temperature range from room temperature to 500 degC and the thermal conductivity was calculated using the measured thermal diffusivity, specific heat capacity, and density data. The result shows that the thermophysical properties of the aluminum series are larger than those of the iron series by 2-4 times. The obtained data are applicable as basic input data in the study of the temperature distribution and in the thermal analysis of brake disks.