Study On The Effects Of Bamboo Charcoal,Carbon Powder And Copper Powder On The Properties Of Friction Materials

With the increasing demand for the use of transport machinery in human society,the use of friction materials is also increasing.The resin based friction material is very popular because of its simple preparation technology,low price,excellent friction and wear properties and mechanical properties.However,due to the thermal property of the resin,the thermal fading phenomenon of the friction materials can easily occur.The main purpose of this paper is to provide a theoretical basis for the research and production of composite friction materials by studying the effects of carbon and copper powder particles on the tribological properties,mechanical properties,thermal properties and wear mechanism of composite friction materials.Based on the control variable method,the constant velocity friction and wear performance test of the modified phenolic resin based friction material with bamboo charcoal and carbon powder was carried out,and the wear mechanism of wear surface was analyzed.The physical properties and mechanical properties of the friction materials were tested by means of shear strength test equipment,beam impact test machine and hardness tester.The thermal performance of bamboo charcoal and carbon powder modified friction material was analyzed by thermal analyzer.The results showed that bamboo charcoal powder can improved the friction coefficient at middle temperature area of the friction material,the effect was the most obvious when the content was 16 wt%,but it had hardly effect at high temperature friction coefficient;Carbon powder can obviously improved stability of friction coefficient and friction coefficient of friction material at high temperature,and the most ideal content of carbon powder was 16~22 wt%;Both bamboo charcoal and carbon powder reduced the bonding strength,thus reducing the mechanical properties and wear resistance of the friction material;About heat performance,the carbon powder can increased the heat stability of friction material at high temperature(above 680?),and improved the high temperature friction coefficient of friction materials,but the excessive carbon powder caused friction and wear properties and mechanical properties of friction materials to become worse.In order to further study on fading performance of friction materials at high temperature,the effects of copper powder on the friction and wear properties and thermal stability performance were studied on the basis of the experimental formula of 11wt% carbon powder.The results showed that the effect of copper powder on the low temperature friction coefficient was not obvious,copper powder can significantly improved the stability of friction coefficient and friction coefficient at high temperature.When the copper powder content was 10 wt%,the heat performance of the friction material was improved,and the thermal conductivity was increased by 33 %.The friction material with copper powder helped to form a stable and compact friction film on the wear surface,wear mechanism changed from the ploughing wear and adhesive wear to abrasive wear and adhesive wear.