Effect of Applied Electric Voltage on Tribological Characteristics of a-CN{sub}x Film Sliding against a Stainless Steel Ball

摘要

The friction test of an amorphous carbon nitride (a-CN{sub}x) coating on an Si wafer against SUS440C ball was carried out with a ball-and-disk tribometer by applying electric voltage to the ball and the disk. The a-CN{sub}x coatings shows ultralow friction in N{sub}2 gas but not in air. Therefore, we tried to decrease the friction coefficient by applying electric voltage to the friction pairs. The friction coefficient decreased with increasing negative voltage to apply to the ball and disk in air. On the other hand, positive voltage increased the friction coefficient. The friction coefficient of CN{sub}X in air decreased from 0.22 to 0.05 by applying electric voltage of DC-200 V. Specific wear rate was decreased with the increasing applied positive and negative voltage. Specific wear rate of CN{sub}X in air decreased from 2.86 × 10{sup}(-8) mm{sup}3/Nm to 1.10 × 10{sup}(-8) mm{sup}3/Nm by applying an electric voltage of DC-200V. When the pressure in the chamber for a friction test is low vacuum as in 1 kPa, applied voltage does not change the friction-and-wear amount of CN{sub}X.