Research On The Dry Friction And Wear Behaviors Of Reaction-Bonded Ti₃SiC₂

The dry friction and wear behaviours and wear mechanism of Ti₃SiC₂ have been studied in this paper by MMW-2 ring on disk end face tribological tester under the conditions of different normal pressure,sliding speed and sintering temperatures.Furthermore,combining with the analysis of microstructures,X-ray diffraction,worn surfaces SEM observation and EDS the friction and wear behaviours and wear mechanism of Ti₃SiC₂ in different conditions were analyzed and discussed,and compared the difference of friction and wear mechanism of Ti₃SiC₂ sintered at different temperature,in order to provide a reference for application of reaction-bonded Ti₃SiC₂ materials as friction pairs using in different conditions.The research indicated that along with the normal pressure and sliding speed's increase,the friction heat enables the friction surface of Ti₃SiC₂ to form a surface film,and increases gradually.The surface film was analyzed as oxide during friction process.The friction coefficient of Ti₃SiC₂ related to the soundness of oxide film,and the more soundness of the oxide film is,the stronger anti-friction is,which causes the friction coefficient to reduce.Under the different pressure,the wear rates of Ti₃SiC₂ were unlike at room temperature and at high temperature.The wear rate of Ti₃SiC₂ tested at room temperature was increased first with the normal pressure,and then decreased.But it would be increased suddenly at high temperature. This is because that the wear mechanism had been changed when the temperature was from room to high temperature.The wear mechanism of Ti₃SiC₂ at room temperature was dominated by abrasive wear primarily,but at high temperature,it was dominated by adhesive wear.The friction coefficient of Ti₃SiC₂ was decreased with the increase of test temperature,but the wear rate would be decreased first and then increased.This is because of the Ti₃SiC₂ with different phases compose sintered at different temperature,and with different amount of Ti₃SiC₂. The impurity phases,such as TiC and C,would affect the friction and wear behaviors of Ti₃SiC₂.The difference of friction coefficient and wear rate between pure and impure Ti₃SiC₂ would be larger with the increase of normal pressure.This is because of higher hardness of TiC.The friction coefficient of Ti₃SiC₂- copper mate would be lower than that of Ti₃SiC₂-steel mate generally.This is because that the hardness copper is lower than that of steel,and copper is easier oxidize than steel when the temperature increase.Thus,the more continuous oxide film would be easy form on surface of copper during friction,which causes the friction coefficient to reduce.The Ti₃SiC₂ material has smaller friction coefficient and very lower wear rate under all kinds of dry friction conditions,and shows better tribology properties and wear resistance.