Research On Morphological Control And Performance Impact Of Lubrication Component Of Cu-Fe Based Friction Materials

As one of the main components of powder metallurgy friction material,the lubrication component has an important effect on tribological properties,wear rate and thermal conductivity.In this paper,high-speed rail imported brake material samples were tested and analyzed,and thus as the foundation to take the lubrication component granulation process of producing carbon black aggregates;explores the complex preparation of pre pressure forming and hot pressing sintering;and the mechanical properties,friction performance and wear mechanism of the friction material were studied.The results show that:(1)The SEM analysis showed that:the lubricating graphite morphology is black thin strips of flake graphite and black thick strip reunion type graphite,graphite lubricating phase content is about 15%.(2)Through the granulation process,preparation of carbon black particles,using a room temperature preforming can make the carbon black aggregates deformed into strip,also can avoid carbon black in the hot pressing sintering process occurs by diffusion and the friction material prepared has good sintering properties and mechanical properties;by granular carbon black particles of preparing friction material performance is obviously better than that of graphite electrode or high strength graphite preparation friction material.(3)With the increase of pelletized carbon black content,the sintering property of friction material showed an overall downward trend,mechanical properties show an overall upward trend;friction coefficient with the braking speed increasing downward trend and with the load pressure increases the downward trend became more and more obvious,braking distance increases with the speed increased nonlinearly.When the particle size of carbon black particles is 40 mesh sieve and hardness of soft particles,carbon black particles with flake graphite ratio of 1:2,the bulk density,porosity,bending strength and compressive strength of the material reached 5.1g/cm3,6.89%,39.89MPa and 69.53MPa,respectively.(4)The experimental analysis of the wear amount of the optimal formula under different operating speed and pressure load is carried out,the process of friction and wear is essentially a new and old process of friction layer.Through the friction surface morphology analysis of friction materials,the friction process accompanied by abrasive wear and adhesive wear,up to a theoretical level and put forward the concept of friction and wear layer.The results of this paper have important reference value and guidance for the practical production and application of high-speed rail friction materials.