Akademik Veri Yönetim Sistemi
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING, cilt.2023, sa.45, ss.1-20, 2023 (SCI-Expanded)
The indexable insert drill, commonly known as the U drill, holds a significant market share of approximately 53% among
drilling tools. Therefore, investigation and improvement studies are carried out by both industry and academia. U drills are
usually produced in different length/diameter ratios and with two coolant holes. But in other cases, some manufacturers
design a third coolant hole in the chip evacuation channel, where the central insert of the U drills is located. It is thought
that the coolant holes and length/diameter ratios change the conditions of the drilling process. In this study, the impact of U
drills with various attributes was examined using thrust force, torque, spindle load, and audio signals. For this purpose, Al
7075-T651 aluminum alloy was drilled with 4 different U drills. The trials used three feed rates (0.06, 0.09, and 0.12 mm/rev)
and three cutting speeds (200, 250, and 300 m/min). Experimental results show that the length/diameter ratio of U drills has
the highest impact on thrust force (76.45%), spindle load (53.33%), and audio signal (87.53%). However, it was ineffective
for torque, according to the Anova analysis. Moreover, the U drill, which has an additional coolant hole, generates higher
thrust forces (39.89%) and audio signals (95.17%), lower spindle loads (41.28%), and lower torque (3.26%). Taguchi based
grey relational analysis that was used to optimize the test parameters provided an improvement of 26.06% according to the
gray relationship grade, which is the normal method used. To sum up, these findings may contribute to improving the design
and production of U drills to enhance their drilling performance.