Recently, lightweight materials centered on the future mobility industry are used in various parts such as battery housings and EV platform frames to improve fuel efficiency of automobile engines. Polycrystalline Diamond (PCD) tools are in demand by parts processing companies to improve productivity for machining lightweight parts. PCD drills have excellent cutting performance and wear resistance in high-speed machining. They are expected to grow in the global cutting tool market in the future. Research is needed to improve their performance. In this study, PCD gun drill and twist drill were respectively manufactured using brazing technology. Comparative machining experiments were then conducted. The PCD gun drill is a straight-shaped tool with a PCD tip brazed to a tool body groove for the tip to enter the cutting edge. The PCD twist drill is a spiral-shaped tool with a PCD drill blank brazed to a V-shaped butt joint with the tool body and an internal groove. Both PCD drills were successfully manufactured and evaluated for dimensional accuracy and surface quality by machining aluminum alloy materials with MCT equipment. In the future, we will evaluate not only aluminum materials, but also various machining materials.

Silicon carbide (SiC) is chemically stable, highly heat-resistant, and resistant to thermal shock. SiC having excellent characteristics in a high temperature and high voltage environment is used in high-power semiconductors, highprecision mechanical devices, optical components, etc. As it is used in various industries, there is a growing demand for processing fine holes or grooves in silicon carbide. In this study, micro holes and grooves were machined on 4HSiC and sintered SiC using electrical discharge machining (EDM). Silicon carbide which has very high hardness can be easily processed by EDM as compared with mechanical processes. As a tool material, a polycrystalline diamond (PCD) which has high wear resistance was used and a micro tool of a diameter of 100 μm was fabricated by wire electrical discharge grinding (WEDG). In the EDM of SiC, the machining characteristics such as surface roughness, discharge gap, and tool wear were investigated.