Preventing insufficient braking force in wading conditions by strategic use of surface texture on brake discs

Abstract

Surface texture technology has been widely used in many industrial fields due to its outstanding antifriction and wear-resistance properties. In this study, groove textures with different quantities and inclined angles are prepared on the surface of a brake disc for high-speed railways. The effects of these textures on the braking capacity and wear resistance of the brake disc under dry and wading conditions are investigated. Results reveal that groove textures significantly reduce the damage caused by abrasive wear on the brake disc surface. The reason is that the grooves can capture and collect debris, which effectively mitigates wear. Under dry conditions, the effect of groove texture on the average friction coefficient is found to be negligible. However, under a small number of dripping conditions, the friction coefficient of the nontextured group drops to 0.04. By contrast, the groove textured groups maintain the lowest friction coefficient between 0.15 and 0.35. This excellent drainage performance of the groove textures prevents the formation of a continuous and whole water film, which ensures effective braking. Under a large number of flushing conditions, the groove textured group requires a shorter number of cycles to recover the initial friction coefficient than the nontextured group. Therefore, groove textures effectively overcome the problem of insufficient braking force during wading. In addition, no linear relationship exists between the quantity and inclined angle of grooves and their ability to suppress braking force deficiency. The groove texture is more conducive to improving braking capacity when the number of grooves is 6 and the direction is aligned with the friction direction.