Cutting edge preparation to improve drilling tools for HPC processes

High material removal rate, high cutting parameters and, hence, high resultant forces are characteristics of high performance cutting. Due to these greater requirements on cutting tool material with respect to its strength and wear resistance, as well as the applied coating, the cutting edge design also gains in importance. By cutting edge preparation, the process reliability can be enhanced through a reduced chipping and a defined rounding along the cutting edge. In this research, the abrasive water jet blasting process was used to prepare different cutting edge designs of carbide twist drills prior to coating. Based on the results of drilling tests using high performance cutting conditions, it was determined that the high performance process can be effectively optimized with respect to workpiece quality and tool life by selectively varying the microscopic cutting edge form.