Material transfer mechanism during magnetic field–assisted electric discharge machining of AISI D2, D3 and H13 die steel

Abstract

In this study, the surface modification and metallurgical analysis of three commonly used die steels were analyzed by microstructure and X-ray diffraction analysis after electric discharge machining and powder-mixed electric discharge machining. The effect of many process parameters was assessed for surface modification using magnetic field–assisted electric discharge machining process. It was observed that the microhardness of the machined surface increased by more than 200%. The analysis of machined surface confirmed material migration from added powder, dielectric and electrode. The magnetic field assisted in improving the material removal process. The strength of the magnetic field resulted in better expelling of material from workpiece and restricted the material migration from electrode especially in copper-based diamagnetic material. Deposition of tungsten and titanium carbide was observed, which increased the microhardness significantly. Titanium, tungsten and graphite powder aided favorably the increase in the microhardness.