Tool wear coated with PCD in high-speed milling of graphite

The rising need for manufacturing molds with increasingly smaller deadlines and costs is demanding from the toolmakers to customize and enhance their fabrication processes; one of the ways to achieve that is by improving their electrode machining, since this process will affect directly in the result of the dimensional precision and production time of the mold. The usage of graphite as raw material for electrodes is known to be highly satisfactory since the graphite has the advantage of machining faster and allowing a great variety of geometrical forms; however, its main disadvantage is that the graphite also has a high level of wear during the machining process. Therefore, this study has evaluated the behavior of the flank wear and the graphite finish by testing specimens against variables, such as cutting speed, feed per tooth, and coating with the use of high-speed milling machining. The results found on the tests have shown that the combination of variables that generated the lowest flank wear was the use of cutting speed of 700 m/min, feed per tooth of 0.07 mm, and application of diamond coating. From those variables, the coating was the one that most influenced the flank wear. Regarding the finish, the parameters that generated the lower surface roughness were the cutting speed of 400 m/min, feed per tooth 0.04 mm, and a diamond coating, in which the parameter that most influenced the finish was the feed.