Investigate the Fluctuation Size in Thrust Force and Chip Morphology in Drilling

Abstract

Drilling is a widely used production method, having a broad range of applications taking part in machining operations. The length of the cutting edge of the drill causes variations in cutting speed, resulting in undesired outputs. In order to decrease this adverse impact in drilling, selecting higher point angles is an obligation, associated with three different kinds of feed rates and spindle speeds. The aim of this study is to investigate the effect of feed rate, spindle speed, and point angle on the fluctuation size in thrust force besides the effect of the fluctuation size in thrust force on the surface roughness, tool wear and chip morphology. In conclusion, while higher point angles provided optimum outputs such as lower fluctuation size in thrust force, less tool wear, better surface quality and continuous chip form, the effect of feed rate and spindle speed on these outputs varied depending on each other. With the stability in fluctuation size in thrust force, less tool wear took place, and better surface quality and continuous chip form were achieved. However, due to the effect of vibrations, higher fluctuation size in thrust force caused undesired outputs, such as poor surface quality, more tool wear, removal chip in short and brittle form during the drilling operations.