An Impact of the Cutting Fluid Supply on Contact Processes During Drilling

The article discusses machining blind holes with twist drills, which is one of the most common machining operations. Typical problems for this process are difficulty to chip removal and coolant supply to the machining zone. Also, when chips are removed along the spiral grooves, they rub against the hole's surface, deform, and, as a result, the surface quality deteriorates. For a comprehensive assessment of the drilling process and the influence of various cutting fluids, it is necessary to control all parameters directly in the material removal process. The paper proposes a method for controlling contact loads and cutting temperature along the generatrix of the workpiece when using various compositions of cutting fluids and assessing their effect on the roughness of the resulting surface. The influence of the supply method of the studied cutting fluids is also shown. So the supply of liquids to the cutting zone through the internal channels of the tool contributes to a significant decrease in the cutting temperature and, by reducing the friction coefficient, helps to reduce the surface roughness compared to the most used method of supply-irrigation.