18 - Fluid delivery

Abstract

Cooling and lubrication of the contact zone between abrasives and the workpiece material, i.e., the cutting gap, is influenced directly by fluid delivery into the contact zone and the type of process fluid employed, e.g., neat oils or water-based fluids. Interactions among process fluids, the abrasive tool, the workpiece, and swarf significantly influence process efficiency and workpiece quality. Efficient cooling and lubrication of the contact zone cannot be achieved with inadequate delivery of fluid into the cutting gap. Limited material removal rates (due to high cutting forces and temperatures), excessive abrasive tool wear, deteriorated workpiece surface integrity, low workpiece geometrical accuracy, poor process repeatability, and a high risk of producing scrap parts are the results of insufficient process fluid delivery into the contact zone. The fluid flow within a pipe is controlled by the nozzle installed on the pipe outlet. The volume flow rate of the delivered fluid, the pressure and discharge speed of process fluid through the nozzle, the nozzle's position toward the cutting gap, and coherence and turbulence of the process fluid (which depends primarily on the type and design of the nozzle) are the main factors that influence the efficiency of supplying process fluid into the cutting gap. However, various challenges, including the length of the contact zone between the abrasives and the workpiece material and the high peripheral speed of the tool (which forms an air barrier around the abrasive tool), also impede the fluid delivery. This chapter presents fluid delivery into the cutting gap during abrasive machining, with the grinding process as the focus. Additionally, methods for cleaning abrasive tools with process fluids are discussed.