Disc Brake Pad Corrosion Adhesion: Test-to-Field Issue Correlation, and Exploration of Friction Physical Properties Influence to Adhesion Break-Away Force

Brake pad to rotor adhesion following exposure to corrosive environments, commonly referred to as “stiction”, continues to present braking engineers with challenges in predicting issues in early phases of development and in resolution once the condition has been identified. The goal of this study took on two parts - first to explore trends in field stiction data and how testing methods can be adapted to better replicate the vehicle issue at the component level, and second to explore the impacts of various brake pad physical properties variation on stiction propensity via a controlled design of experiments. Part one will involve comparison of various production hardware configurations on component level stiction tests with different levels of prior braking experience to evaluate conditioning effects on stiction breakaway force. Part two will involve modifying a production friction material formulation with known stiction in the field to force differences in porosity, density, and pH, and thus attempt to correlate stiction propensity with these physical properties. A prior study [1] has explored this potential with non-commercial friction materials of very basic make-up, though this experiment will differ in that the base friction material utilized has production field experience.