Thermal and microchemical investigation of automotive brake pad wear residues

By means of the combined use of simultaneous differential thermal analysis and thermogravimetry (DTA-TG) and scanning electron microscopy + energy dispersive spectrometry (SEM + EDS), the thermal and microchemical investigation of an automotive wear brake pad and its residues produced during the long service of a largely used Italian car, is carried out. The wear residues are produced during braking as the pad releases microscopic debris from the contact surface due to the combination of friction induced heat and mechanical actions such as attrition and wear. The results of SEM + EDS characterisation combined with the results of the thermal behaviour study, show the chemical and physical changes induced in the microchemical structure of the pad during braking and further, allow to measure the surface contact temperature at the interface between brake pad and metallic counter-face that does not exceed 720 oC.