Abstract
KEYWORDS – tribology, in situ observation, acoustic emission, friction and wear mechanism, evaluation method
ABSTRACT
As a new method to evaluate frictional properties more accurately, we have proposed “in situ observation and acoustic emission (AE) measurement method” and examined tribological phenomena on brake pads in our previous report. If we could understand the relationship between AE signals and frictional properties of brake pads, the complex frictional properties of brake pads could be evaluated from measuring their AE signals. In this study, the relationship between AE signals (mainly, the AE frequency spectrum) and tribological phenomena on brake pad materials was examined by an in situ observation and AE measurement method closer to a real-world sliding condition compared from our previous study. From the high-speed in situ observations, it was found that the microscopic deformation and fracture between the sliding surfaces, a crack growth and separation of brake pad materials, abrasion of the rotor material, and adhesion of metallic fiber to the rotor material, could be identified and evaluated from the analysis of AE signal waveforms.