—Micro-electrical discharge machining (EDM) is one of the most effective methods for making holes in machining difficult-to-cut materials, such as tungsten carbide, because the hardness is not a dominant parameter in EDM. However, as die sinking EDM requires the use and subsequent production of tool electrodes, the machining time is longer and costs higher than in cutting methods such as milling by a machining center. The method with a diamond drill is considered one of the most effective methods for making holes. In this study, cemented carbides were holed by electroplated diamond drills with a through coolant hole. Two types of drills with different flute shape, namely with a V-groove and without a V-groove, were used to drill two types of cemented carbides of different hardness. The following results were obtained: (1) No drilled holes showed noticeable burrs or corner dullness. (2) The main tool failure of the electroplated diamond drill was the flaking of the diamond layer on the drill tip. (3) The addition of the V-groove on the drill tip extended the tool life by 1.7 times. (4) Both the drilled hole’s diameter of the entrance side and that of the outlet side decreases with the increase of the drilled hole length. (5) The tool life of the electroplated diamond drill was dependent on the hardness of the cemented carbide.
—Cutting performance, electroplated diamond drill, cemented carbide, unique flute.
Tadahiro Wada is with the Nara National College of Technology, 22 Yatacho Yamatokoriyama Nara, 639-1080, Japan (e-mail: firstname.lastname@example.org).
Cite: Tadahiro Wada, "Cutting Performance of Electroplated Diamond Drill with V-Shaped Groove and through Coolant Hole in Drilling Cemented Carbide," International Journal of Materials, Mechanics and Manufacturing vol. 5, no. 2, pp. 79-82, 2017.