Improved cemented carbide properties after wire-EDM by pulse shaping

In many applications the wire-EDM of cemented carbides (WEDM) (WC–(TiC)–Co) is restricted by the basic properties of this family of materials. Therefore, this research was aimed at developing an optimal process energy source that produces improved material properties after WEDM. The studies showed that it is important to use the correct parameter selection for main-cut and post-cut. Deterioration in the material properties by processing with high pulse energies can be corrected only by a limited extent in the post-cut. The primary actuating variable of pulse is the pulse duration, i.e. with pulse duration <500 ns higher current magnitudes can also be used without problems. Through the use of a new process energy source increase of bending strength of average 30% could be achieved. Simulation of the pulse waveforms and how the thermal load of the cut surface can be reduced and the technical conditions can be adapted to a particular application are shown in this paper.