The effect of tungsten introduction on the tribological properties of Si3N4 ceramics paired with GCr15 steel under nonlubricated conditions

Abstract

Silicon nitride ceramics were fabricated by gas pressure sintering using Y2O3 and Al2O3 as sintering aids, and 5 vol% tungsten particles were introduced to improve their wear resistance. The tribological properties of silicon nitride ceramics were tested as well as the relative density, hardness, flexural strength, and fracture toughness. During the wear process, the introduction of tungsten particles changes the morphology of the worn area and has a positive effect on wear reduction and lubrication. As a result, the friction coefficient of the system decreases, and the wear rate of silicon nitride ceramics is reduced to approximately half of the original. Tungsten particles were found to be a new lubricating phase for silicon nitride ceramics.