Abstract:The electric spindle of machine tool can obtain higher speed to realize high speed and high efficiency machining when using the low viscosity lubrication medium,and because of its advantages of small expansion coefficient,good heat conduction performance and shorttime dry friction resistance,graphite bearing is especially suitable for using at the condition of low viscosity lubrication medium.In order to select a suitable material of graphite bearing to meet the need of high speed machining,through the analysis of the spindle working condition,the demand parameters for the material of graphite bearing were obtained.The graphite material performance testing system consisting of material mechanics experiment,thermal physics experiment and tribology experiment was designed.Four kinds of common graphite materials were selected,and their mechanical properties,thermal physical properties and friction and wear properties were tested and evaluated.The reasons for differences in performance were explained from the microstructure.The research results show that the graphite materials with moderate degree of graphitization and after impregnation process are more suitable for using as the material of highspeed spindle bearing.