Large-diameter hole drilling for Carbon-Fibre-Reinforced-Polymer (CFRP) is challenging
because of its non-homogeneity and anisotropic features. This research will illustrate
the hand-laminated and unidirectional CFRP based on three-hole making strategies for
helical milling, large hole and pilot hole drilling. In this article, CFRP analyzes
and optimizes axial cutting force and Delamination Factor (DF) based on experimental
data collected at different FR (Feed Rate). CFRP's large diameter hole quality analysis
includes cutting speed (Rotational Tool Speed) and scanning electron microscopy (SEM)
analysis of helical milling, pilot hole and large hole drilling. A comparative study
between large hole diameter, pilot hole drilling, and helical milling of CFRP was
also conducted to discover the better technology for hole calibration quality by analyzing
Machining Force (MF) and DF. According to experimental tests of CFRP laminates, the
MF is proportional to the FR. Compared to helical milling, pilot hole drilling with
proper cutting parameters can create superior quality holes. As a result, it is recommended
that pilot hole drilling be done at a low feed rate and a high rotational tool speed
for optimum hole quality. The hole calibration was analyzed to distinguish the cutting
parameters (Cutting Speed, FR, and MF) to reduce DF and improve hole quality. Low
FR was necessary for CFRP high-speed drilling because delamination at the hole exit
was a concern.
