INFLUENCE OF DRILLING PARAMETERS TO THE CHIP FORMATION OF MACHINING ALUMINUM 6061 USING HSS TWIST DRILL

Abstract

ABSTRACT - The influence of drilling parameters on chip formation during the machining of aluminium
workpieces using High-Speed Steel (HSS) tools plays a critical role in optimizing the process for
enhanced efficiency, surface quality, and sustainability. Drilling parameters like cutting speed, feed rate
and drill bit point angle can significantly influence the machining performance. This research
investigates the relationship between key drilling parameters such as spindle speed, feed rate, and drill
bit point angle to the chip formation and hole surface roughness. Design of experiment (DoE) using
Response Surface Methodology (RSM) was employed to optimize the experimental work. The
machining operation employed a CNC machine to drill a hole on aluminum 6061 using 10mm HSS twist
drill. The input parameters studied are spindle speed, feed rate and tool drill point angle while the chip
formation and surface roughness are considered as an output parameter. The result reveals that
Continuous, segmental and discontinuous chip are produced at drill bit angle of 90°, 118° and 135°
respectively. In addition, the ANOVA analysis identifies that the point angle is the most significant factor
contributes to surface roughness of drilled hole of p-value of 0.0001 which then followed by spindle
speed of p-value of 0.0103. Both spindle speed and point angle critically determine surface roughness,
with lower spindle speeds and larger point angles resulting in rougher surfaces due to discontinuous
chip formation. These findings provide valuable insights into optimizing drilling parameters to achieve
desired machining outcomes, thereby supporting the development of more efficient and sustainable
manufacturing processes.