Cold wear of brake disc related to brake induced vibrations

Abstract

The cold wear of brake disc is a phenomenon related to judder and other kinds of vibrations. The mechanism and the parameters concerning the cold wear of the disc are the basis for the comprehension of the sources of brake induced vibrations. As a continuation of prior research, a tribometric study was conducted with different disc materials: grey cast iron and inox steel. The wear rates of the above materials were measured at different pressure levels and with the same initial temperature. A parametric model was developed to correlate disc thickness variation (DTV) measurements of the different friction couples with variables affecting DTV. The final model of disc cold wear takes an easy form compatible with the proposed mechanism of wear. The balance among oxide layer-transfer, layer growth and heterogeneous wear is determinant for DTV formation and consequently, brake induced vibrations.