Effects of the cutting fluid reduction on the dimensional quality of holes

Drilling is one of the machining processes most used by manufacturing companies and is very complex from the perspective of scientific study. The geometry and the surface are generated in a single operation with many influential parameters. Geometric and dimensional control are more critical when the use of cutting fluids is reduced or eliminated because the temperatures in the process can influence the shape and the dimensional accuracy of the holes. However, this influence is not completely understood. With this goal, this article presents a dimensional analysis of holes made with carbide drills in AISI P20 steel under the fluid application of emulsion, minimal quantities of lubricant and dry machining. The dimensional parameters analyzed were the diameter and the circularity of the holes. Special highlight can be given to shape results, which were evaluated at different depths (beginning, middle and end of the hole), and along the evolution of the number of holes. Some differences of the investigated results compared to the literature are due to the formation of adhesion on the wall of the hole, resulting from passage of the edge on this particular severity condition.