Experimental Investigation of EDM Parameters for TiC/Ni Cermet Machining

Abstract

Electrical discharge machining (EDM) is an effective method for TiC/Ni metal ceramic processing. In this paper, the influence of peak current, pulse duration on the surface roughness, material removal rate and material removal mode (MRD) is studied. Experimental results indicate that with the increase of peak current, the surface roughness and material removal rate increases gradually; with the increase of the pulse duration the surface roughness of the workpiece increases gradually, the material removal rate increases first and then decrease. The machined surface are measured by a scanning electron microscope (SEM), when the peak current is small, the main MRD is melting, gasification of nickel and TiC and integrate grains removal of TiC, it turns to be more obvious of melting, gasification of nickel with the current increase. The change of pulse duration has little effect on the MRD, which is mainly melting, gasification of nickel and TiC and thermal explosion spalling of TiC.