Weibull approach to brake pad wear analysis in the Nigerian market

In this study, we evaluated the wear properties of four brands of brake pad available in the Nigerian market. In particular, we assessed the tribo performance and service life of the brake pads. We purchased four commercial brands of brake pads used in light duty cars and coded them as AU, SN, TY and SM, respectively. A small piece of the brake pad lining materials was carefully chiseled from the back plates to obtain samples for the experiments. We conducted Brinell hardness tests using a tensometer and a pin-on-disc test rig to determine the coefficient of friction and the wear characteristics of the materials. We then correlated the wear on each set of brake pads with the running time and used Weibull's equation to determine average service life. Sample TY exhibited the highest hardness value (29.09) and sample SN the lowest (10.05). The determined coefficients of friction ranged between 0.3-0.36, with sample AU exhibiting the lowest value and sample SM the highest. Sample SN showed the lowest wear rate of 3.53 x 10(9) g/min, while the wear rates of samples TY, AU, and SM were 5.64 x 10(8), 8.19 x 10(9), and 2.10 x 10(8) g/min, respectively. The relative service life of samples SN, TY, and AU were similar, with average values of 2778.09, 2725.41, and 2717.34 min, respectively, and SM had a relatively low service life (2017.82 min). We conclude that the overall performances of Nigerian brake pads do not meet all the specifications for friction materials used in road vehicle brake linings and pads.