Effect of varying cashew dust and resin on friction material formulation: stability and sensitivity of µ to pressure, speed and temperature

Inconsistent friction level during braking at different speed and pressure is a major concern to the brake pad/lining manufacturers as it is proven to be a formulation dependent. The behaviour of friction of an NAO brake pad is highly complex under a set of dynamically variable pressure speed and temperatures. This paper examines the sensitivity of friction (μ) towards braking pressure and sliding speed. Normally, the organic components burn off at elevated temperature, reducing the brake effectiveness and hence its temperature sensitivity is also carried out by fade test. This paper discusses the effect of organic components, namely resin and the cashew friction dust in a disc brake pad formulation. Three pads with varying resin (10.11, 11.11, 12.11 percentage by weight) and the cashew dust (9.33, 10.33, 11.33 percentage by weight) are fabricated and their effect in relation to stability of friction is studied by carrying out the test on the inertia dynamometer following JASO C 406 schedule. Optimisation of the ingredients is carried out using the response surface methodology. It is observed that composites with 10.11% resin and 9.33% cashew dust resulted in better performance with consistent friction level viz. least sensitivity of μ to operating variables, namely speed and pressure by carrying out a regression analysis.