Effect Of Exogenous Third Body Powders On The Friction Properties Of Brake Pad

With train speed rise, braking system is bearing gigantic loading and momentum, theproblem of the braking stability is outstanding gradually, the discussion of the friction factoris becoming an important factor to improve a train working safely. Among them, the thirdbody formed on the friction surface is an important actor which affects friction property. Themechanism therefore, impacts of third bodies to the friction property systematically, andclarifying each element of the third body clarification of the role, becomes the importantfactors of research and development of high performance friction material.The friction and wear tests are performed in GF150D testing machine with constantspeed. The material of dual discs is made of H13. In this paper, we study added copperpowder, aluminum powder, iron powder and SiO2powder independence on the frictionmaterial of Q235steel. Study on effect of the third body on the friction performance underdifferent friction orders, friction pressures, friction speed, in order to know the friction andwear mechanism under different friction condition. The result shows that:The friction coefficient is increased after added copper powders the increased extent offriction coefficient is about the adding method, the hole way to increased over0.2, and thesprinkle way to increased about0.1~0.2, the reason is that hole way content added is higherthan sprinkle, the stabilization of deformation and viscous flow of the third body of copperpowder increased the mating degree, and the friction is increased.After added aluminum powder, the friction coefficient is increased0.1, the effect of theway to added powder is not so obviously, and the friction coefficient is decreased as the speedis increased, the dry friction coefficient higher than wet friction coefficient under low speed,while at high speed is opposite, the influence to friction coefficient of aluminum powder islower than copper powder, the reason is that the hardness of aluminum oxidation is high, andthe deformation degree is worse, the mating degree is worse.The friction coefficient after added iron powder is changes not so obviously at low speed.As the speed is over1500r/min, the friction coefficient is increased0.1. The reason is thatalmost the same nature between iron powder and the surface of friction pair. The oxidation isexacerbated at high speed, which means that the content oxidation of the third body isincreased, and the friction coefficient is increased.The friction coefficient is a little changed after added SiO2powder. As the SiO2powderis brittle oxidation, and the rolling friction is resistant with furrow during friction process. Sothe friction coefficient is a little changed...