抄録
In order to know the running-in process for ultra low friction of CNx sliding against Si_3N_4 balls in N_2,the effect of surface roughness of balls on friction coefficient was investigated. As results, it was shown that friction coefficient for all of Si_3N_4 balls decreased with sliding cycles and reached to the specific minimum values less than 0.05. For friction coefficient less than 0.01,smooth surface of ball with 30nm Ry as initial surface roughness was necessary. Smooth surfaces of CNx coating and Si_3N_4 ball after running-in provide ultra low friction after the transfer of tiny amount of CNx to Si_3N_4 ball and the generating of thin and uniform transfer film on balls.
