Friction and wear behaviours of YG8 sliding against austempered ductile iron under dry, chilled air and minimal quantity lubrication conditions

Abstract

In this study, to investigate the friction and wear behaviours of cutting tools made of YG8-cemented carbide in the process of cutting austempered ductile iron, friction and wear tests at different applied loads (100–500 N) and sliding speeds (40–120 m/min) under conditions of dry, chilled air and minimal quantity lubrication were carried out using a tribometer and a composite spray cooling device. In addition, the morphology and material transmission of the worn surfaces were analysed by scanning electron microscopy and energy dispersive spectroscopy. The results showed that the wear rates of the YG8 pins increased with increasing applied loads; however, the sliding speed exerted no significant influence on wear of the YG8 pins. Under dry conditions, the worn surface was mainly found to exhibit abrasive wear under a low load. With increasing loads, the transfer films were formed, and then led to fracturing and spalling of the frictional surfaces. Under chilled air and minimal quantity lubrication conditions, the worn surface was smoother than that under dry conditions. The most favourable results were obtained under minimal quantity lubrication condition due to the oil film formed on the surface of the frictional pairs.