The investigation of different additive materials and process conditions on the tribiological properties of the high density polyethylene (HDPE)

In this experimental study, the tribological behaviors of pure high density polyethylene (HDPE) and HDPE composites containing different amount (5%, 10% and 15%) of mussel shell powder (MSP), silicon dioxide (SiO2), zinc oxide (ZnO) and zinc borate (ZnBr) fillers. Friction and wear tests are performed in dry sliding conditions, at room temperature of 23°C and 50% humidity on a pin-disc wear test apparatus. Experiments are performed at different loads (60N, 100N and 140N) and different speeds (such as 1.0, 2.0 and 3.0 m/s) by using against AISI 316L stainless steel disc on 2000m sliding distance. In a consequence of friction and wear tests, friction coefficient and specific wear rates of pure HDPE polymer and its composite materials used are determined. In addition, the effects of applied loads and sliding speeds to the specific wear rate and coefficient of friction are examined. It is determined in tests that the highest specific wear rate belongs to HDPE+15%ZnO polymer composite with a value of 4.49x10-14 m2/N and the lowest specific wear rate is observed in HDPE+15%MSP composite with a value of 1.59x10-15 m2/N. Wear surface examinations of pure HDPE polymer and filled HDPE composite materials are made by using optical microscope.