Proposed Metrological Method for Identifying Automotive Brake Discs 2015-01-0691
The main aim of this work is to develop an identification method to demonstrate the crucial surfaces of automotive braking system. Two brand new brake discs manufactured by two different manufacturers are tested. A typical disc to the one of them was put under working condition in actual braking system. Dimensional and geometrical deviations are investigated using advanced engineering metrological technique. Mechanical properties, tribological characteristics and chemical analyses are investigated. A coordinate measuring machine, universal hardness tester, mass comparator and XRF spectrometer are used in these diagnoses. Measurements of dimensional and geometrical deviations such as disc thickness variations, thickness deviations, straightness, parallelism, runout of disc surfaces are conducted. A comparison between form deviations in disc surfaces have been carried out and analyzed. The effect of material properties of the influencing surfaces on the wear rate and hardening of surfaces has been discussed. Wear rate under severe sliding conditions is thus strongly influenced by the geometrical and hardness characteristics. The wear rate of used brake disc rotor induced fatigue phenomena is accurately identified. Correlations between design specifications and real surface characteristics are evaluated. The results showed that implementation of the engineering metrology techniques to understand and predict the dynamic behaviors for auto brake discs are necessary successful. Moreover, repeatability of the measurement results is conducted to confirm their precision.