Tribological performance of polymer composites used in electrical engineering applications

Dry sliding wear characteristics of commercially available poly-ether-imide (PEI)+20% ( glass fiber reinforced)GFR and polysulfone (PSU)+20% GFR polymer composite in use in electrical engineering applications were investigated using a pin―on―disc rig. Pin materials are (PEI)+20% GFR and PSU+20% GFR polymer composite. Disc materials are AISI 4140 steel and PA 46+30%GFR polymer composite. Wear tests were carried out at 0.5 and 1.0 m/sec sliding speeds and 20, 40 and 60N load values and under atmospheric conditions of temperature and humidity. Different combinations of rubbing surfaces were examined and the dynamic friction coefficient and specific wear rate values were obtained and compared. For all material combinations, the coefficient of friction shows little sensitivity to sliding speed and applied load values and large sensitivity to material combinations. For specific wear rate, PEI composite has shown little sensitivity to change in load, speed and materials combination while PSU composite shown large sensitivity to the change in load and material combinations. The friction coefficient of PEI+20%GFR and PSU+20GFR rubbing against AISI 4140 steel disc is a round 0.3 and is about 0.12 as rubbing against PA 46+30%GFR. The specific wear rate for PEI and PSU composites are in the order.of 10 -15 to 10 -14mm3 /N.m. The wear mechanisms are a combination of adhesive and abrasive wear.