The Study On Properties Of Friction Materials Reinforced By Carbon Fiber

With the continuous development of society and the industrialization progress,Friction materials play an important role in our daily life and are widely used inautomobiles and train brake system. Friction materials should not only has goodabrasion resistance, stable friction coefficient, good mechanical and physicalperformance, but also has the qualitative light, braking without noise, no pollution tothe environment, lower cost etc. Carbon fiber has good abrasion resistance, highthermal conductivity, good tensile performance, no pollution to the environment,qualitative light etc. therefore Carbon fiber will become a new generation of frictionreinforced materials.This paper mainly studies on the performance of carbon fiber friction materials.Substrate materialsare barite ore, graphite, powder, kaolin, resin and aluminum oxide,by adding different length and content of carbon fiber,and suppressedin the mold. Thefriction coefficient, wear rate, impact strength and hardness are measured byexperiment instrument and analyzed.Through the experiment, carbon fiber can change the friction coefficient offriction material. Along with the increase of carbon fiber length, friction coefficientfirst increases, then decreases. When the content andlength of carbon fiber are same,the coefficient of friction materials decreasewith the increase of the ratio of pressure.The carbon fiber will change the wear rate of friction materials. With differentlength and content of carbon fiber, wear rate of friction materialsare also different.With2%content of carbon fiber and different length of carbon fiber, Frictionmaterials’ wear are relatively stable. When the Content of Carbon fiber is4%and6%,with the increase of the length of carbon fiber, wear rate of friction materials decrease,then increase, and are higher than friction materials with2%carbon fiber.Underdifferent pressure, without or with carbon fiber,wear rate of friction materials aredifferent.With the increase of the pressure, wear rate of friction materials increasewithout carbon fiber; reducewith2%Carbon fiber;increase with4%Carbon fiber. withthe content of carbon fiber is6%, wear rate of friction materialsreduce when thelength of Carbon fiber is less than1000μm andincreasewhen the length is more than1000μm.The surface of friction materials is relatively smooth with20μmcarbon fiber. thesurface of friction materials are relatively slightly rough with1000μm,3000μ m, anddifferently distribute grits, large area off and emergence pits of carbon fiber, scratchesparallel to the direction of sliding and bare bundle carbon fiber near the frictionsurface.When the surface roughness is in2.0-2.3μm, wear performance of materials arevery well.Different length and content of carbon fiber differently increase the hardness offriction materials. When the content of carbon fiber is same, the harness of frictionmaterials increasesalong with the increase of the length of carbon fiber.Along with the increase of carbon fiber, the impact strength of friction materialsfirst increase, then decreaseswith2%carbon fiber. The impact strength decreased, andthen increase with4%and6%carbon fiber. Surface of friction materials withoutcarbon fiber are relatively smooth and the surfaces of carbon fiber friction materialsare uneven.