Effect of Machining Parameters on Surface Roughness and Dimensional Accuracy of Micro Drilling for Copper

Drilling is one of the basic machining process of making holes and that is is essential for
manufacturing industry. Therefore optimization of the parameters that control the process of
micro drilling is unavoidable in order to have the best results. In this study the parametric
optimization of micro drilling has been studied by considering a number of parameters such as
spindle speed, feed rate and drilling tool size on material removal rate (MRR), surface
roughness, dimensional accuracy. In this work, a study has been done on optimum drilling
parameter for carbide drilling tool in micro-drilling processes in order to find the best drilling
parameter for copper as a work piece material. Micro drilling experiment with 2.3mm to 2.6 mm
drill sizes were performed by changing the spindle speed and feed at three different levels.
Comparative analysis has been done between surface roughness, MRR and dimensional accuracy
of drilled holes by experimentation. From the result, the surface roughness are mostly influenced
by spindle speed and feed rate. As the spindle speed increases, the surface roughness will
decrease. However the surface roughness increases with increase in feed rate. The value of
MRR decrease when the tool diameter, spindle speed and feed rate decreases. As drilling tool
diameter, feed rate and spindle speed increase the dimensional accuracy of drilled hole will
decrease. The increment of spindle speed and feed rate value will affect the tool wear.