FME TRANSACTIONS, cilt.50, sa.3, ss.441-460, 2022 (ESCI)
In this study, machinability tests were carried out to investigate the effects
of control factors (cutting tool geometry, cutting speed, and feed rate) on
the surface roughness (Ra), deviation from dimensional accuracy
(Da_dev), roundness error (Re) in drilling CFRP/Ti6Al4V mixed metallic
stack and to determine the optimum levels of drilling parameters. The
effects of each control factor and their interactions on three quality
characteristics were analyzed, and their levels were single-objectively
optimized for each component material by the Taguchi method. The
material has components (CFRP and Ti6Al4V) with essentially different
properties (mechanical, physical, machinability). Single-objective optimi–
zation has limited usability as the drilling must be performed in one
through both layers. Therefore, in an additional step, the optimum levels of
the control factors were determined by optimizing multi-objective with the
Additive Ratio Assessment (ARAS) method. Higher Ra, Da_dev, and Re
values were obtained on the CFRP component compared to the Ti6Al4V
component. The CFRP/Ti6Al4V stack should be drilled with a nano fire
coated carbide drill (T3) at medium cutting speed and high feed rate to
achieve minimum Ra, Da_dev, and Re values in one go.