Tribological and thermal effects of cutting fluid application in machining with coated and grooved cutting tools

The use of Cutting Fluids (CFs) in machining operations is being increasingly questioned in recent years for environmental and economic reasons, leading to efforts in promoting dry, as well as minimal quantity of lubricant (MQL), machining. However, the tribological effectiveness and thermal aspects of CF action at modem cutting conditions, which not only involve relatively high cutting speeds but also advanced tool coatings and chip-breaking geometric features, need better understanding. This paper presents an experimental investigation into the effects of different CF application methods on various machining performance measures while cutting with commercially available flat-faced, as well as grooved, uncoated and coated cemented tungsten carbide tools. CF effects under dry, flood, and MQL conditions, were gauged through their influence on cutting forces, tool temperatures, tool-chip interfacial contact, and chip morphology during machining of AISI 1045 steel. The results show new trends on the individual cooling and lubricating effects of CF application methods, and the effects of their interactions with the tool coatings and the presence/absence of chip-breaking grooves.