Effects of Transferred Surface Film on μ Behavior of Disc Brake Pad in Humidity Environment

The disc brake pad is a part that is expected to exert the stable performance in a wide variety of working conditions, for example, in a wide speed range and in a wide temperature range. In addition to these working conditions, the stable performance in a variety of humid conditions has also been demanded. This is because most non-asbestos brake pads have the low friction coefficient μ in high humid conditions, which affects the performance of the disc brake pad.

This study notes the film of the friction material on the disc rotor as the reason of a decrease in friction coefficient μ in the high humid environment and discusses the mechanism of the decrease in friction coefficient μ.