Tribological Characteristics of Ti₃SiC₂/Cu Tribo-pair in Sliding Electrical Contact

The tribological characteristics and contact resistance of Ti₃SiC₂/Cu tribo-pair in sliding electrical contact were investigated under dry sliding in air and lubrication of ion liquid LP106. Under dry sliding,friction coefficient was as high as 0.6 at a sliding speed of 0.11 m/s. Increasing sliding speed up to 0.33 m/s increased the friction coefficient but reduced the contact resistance. In addition,transfer film of Cu was observed on the worn surface of Ti₃SiC₂ pin. Instability of contact and electric sparking at sliding speeds of 0.44 and 0.56 m/s indicated severe wear in forms of mechanical and electrical wear and their synergetic effect. Under lubrication of minimal quantity (15 μL) of LP106,the lubrication regime was boundary lubrication, friction coefficient was as low as 0.08 at 0.11 m/s and increased to 0.12 at 0.22 m/s and 0.2 at 0.56 m/s. At speed higher than 0.33 m/s,ploughing of Cu disk by hard asperities on Ti₃SiC₂ pin resulted in the formation of long and curly Cu wire with an average diameter of 53 μm and lengths up to several centimeters. The presence of Cu wire swept a small amount of ion liquid out of the frictional surface and had detrimental effects on tribological and electrical properties.