Improving tribological behaviour of piston ring-cylinder liner frictional pair by liner surface texturing

Experiments were carried out on a reciprocating tester. The lubricant was supplied into the inlet side of the contact zone. The construction of tribological tester allows to measure the friction force between specimen and counter-specimen. Tribological behaviours of cylinder liners with and without oil pockets were compared. Specimens were cut from plateau honed cylinder liners made of grey cast iron. Counter-specimens were cut from grey cast iron piston rings. A special tool acted as a hammer to form additional dimples on the liner surfaces. The area density of oil pockets was about 13%. Specimen surfaces had dimples with average depths about 5 pm and diameters in the range 0.15-0.2 mm. Two batches of tribological tests were carried out, in regimes of full and starved lubrication. Friction tests were conducted at three mean sliding speeds: 0.44, 0.66 and 0.88 m/s. Experiments were performed with normal load in the range 50-300 N, starting from the lowest load. Normal load increased in a stepwise manner after 2 min at each load, until the maximum load was reached. Areal surface topographies of specimens and counter-specimens were measured before and after two batches of tests by white light interferometer. (C) 2012 Elsevier Ltd. All rights reserved.