Microscopic evaluation of chemical and morphological changes in automotive brake materials in relation to friction process

Abstract

This diploma thesis deals with characterization of surfaces of brake pads for passenger’s cars before and after their testing on the brake dynamometer. Three types of brake pads - reference, modified with kaolin and modified with nanocomposite kaolin/TiO2 are analysed and compared. For their characterization, selected microscopic techniques are used, such as digital optical microscopy and scanning electron microscopy. The TIMA microscope was used to study the phase composition of the friction layer. The chemical and phase changes are best illustrated by the phase maps taken. The intermetallic phase of Fe-Cu oxide dominated the friction layer of all evaluated brake pads after testing, and its presence could be understood as the direct consequence of locally occurring temperatures above the melting point of the individual elements.