Wang, S., Zhang, J., Yang, Z., and Chen, K., "Characterisation of the Brake Pads Used in High-Speed Trains," SAE Technical Paper 2013-01-2028, 2013, doi:10.4271/2013-01-2028.
It is essential to characterize the frictional properties of brake pads used in high-speed trains during the processes of development and manufacturing of the pads. This paper presents the test results of new developed composite and powder metallurgical brake pads at different sliding speeds and contact pressures with specially designed test rig.Test results show that the coefficient of friction was increased with the increasing of sliding speed up to 120km/h, but over 120km/h it was decreased with the increasing of sliding speed for the composite brake pads. For the powder metallurgical brake pads, sliding speeds had no significant effect on the friction coefficients of the brake pads. Contact pressure had significant effect on the friction coefficient of brake pads for both materials. Water on the braking contact surfaces had significant effect on the friction coefficient of powder metallurgical brake pads. Temperature had significant effect on the friction coefficient of the powder metallurgical brake pad 2-T5 but had no significant effect on 1-T5.The braking squeal generated from both brake pads of composite material and powder metallurgical material has been investigated. It has been observed that powder metallurgical braking pads were likely to generate squeal but composite brake pads were not. Both sliding speed and contact normal pressure play a significant role on the generation of braking squeal.