Wear behaviour of plasma-sprayed partially stabilized zirconia on a steel substrate

Abstract

In this experimental investigation, various layers of partially stabilized zirconia (PSZ) coated on steel by plasma spraying were studied to gain a better understanding of the tribological behaviour of PSZ under the conditions of dry contact in a reciprocating motion at a temperature of 200 °C, which represents the severe operating conditions of friction pairs, such as cylinder liner-piston ring. The parameters investigated in relation to the wear behaviour were the thickness of the coating, oscillating frequency, sliding cycle and applied load. To identify the wear mechanism, X-ray diffraction, scanning electron microscopy and optical microscopy were used. In comparison with a steel-steel pair, PSZ coating-steel and PSZ coating-PSZ coating pairs exhibit far better wear characteristics and, therefore, the distinct possibility of applying a plasma-sprayed PSZ coating as a cylinder liner has been confirmed. The oscillating frequency and applied load conversely affect the wear rate of disc. The recommended coating thickness was found to be in the range 180–300 μm to ensure good anti-wear behaviour without the expense of high coating cost.