Preparation And Properties Of Fe-Cu Based Friction Materials For Light Vehicles

With the increasins speed and light weight of transportation,people pay more attention to travel safety.Braking friction material is an important guarantee for vehicle brake safety.Among the commonly used powder metallurgy friction materials,the iron-based friction material has serious adhesion to the dual bond,the brake is unstable,and it is easy to damage the dual;when the copper-based friction material and the iron pair are rubbed,although the friction coefficient is stable and the wear rate is low,the price is low.More expensive.The iron-copper-based friction material combined with the two has the advantages of high temperature resistance of the iron base and large strength of the base,and also has the advantages of good copper-based thermal conductivity and stable friction coefficient.In this paper,Fe-Cu based friction materials with different matrix components,friction components,lubricating components and carbon fiber content were prepared by powder metallurgy method,and the feasibility of preparing Fe-Cu based friction materials by groutins-infiltration method was discussed.The microstructure,phase composition?mechanical properties and tribological properties of the friction material were analyzed by metallographic microscope,X-ray diffractometer,scanning electron microscope,Vickers hardness tester,universal testing machine,impact tester and friction and wear tester.Finally,the influencing factors of friction coefficient and the formation mechanism of friction layer in Fe-Cu based friction materials are discussed.The results show that:(1)Among the Fe-Cu based friction materials with different matrix components,the friction coefficient of the sample containing Fe50Cu20 is 0.61?but the friction coefficient is stable.In the samples of different friction components,the friction coefficient of SiC-containmg friction material is 0.73,but the most Unstable,mixed SiC,Al2O3 and zircon sand samples,the friction coefficient is the most stable 0.65;friction component ratio is SiC:A1203:zircon sand has the most stable friction coefficient when 4:3:2,friction coefficient The friction coefficient of the Fe-Cu based friction material containing 2%carbon fiber prepared by grouting-infiltration method is stable at 0.58.(2)The carbon fiber mass fraction is 2%,and the friction material has the best mechanical properties and tribological properties.The density is 92.6%,the hardness is 118.6 HV,the shear strength is 35.624 MPa,and the impact strength is 5.7 J/cm2.At normal temperature,the coefficient of friction is 0.6,and the loss on grinding loss is also 0.0038 g.At 400 ?,the coefficient of friction is reduced to 0.56.And the phenomenon that oxidation increase is more important than the loss of grinding loss.The friction mechanism is mainly abrasive wear at normal temperature,accompanied by a small amount of adhesive wear,and at high temperatures,mainly oxidative wear.(3)The factors affecting the friction coefficient of Fe-Cu based friction materials and their influencing mechanisms are discussed.The main influencing factors of friction coefficient are material and temperature.The influence of carbon fiber on the friction coefficient is large.The carbon fiber-reinforced Fe-Cu based friction is analyzed.The friction process of the material is considered to have gone through three stages,namely the running-in phase,the transition phase,and the stabilization phase.