The effect in EDM of a dielectric of a urea solution in water on modifying the surface of titanium

This study investigates the influence of the machining characteristics on pure titanium metals using an electrical discharge machining (EDM) with the addition of urea into distilled water. Additionally, the effects of urea addition on surface modification are also discussed. In the experiments, machining parameters such as the dielectric type, peak current and pulse duration were changed to explore their effects on machining performance, including the material removal rate, electrode wear rate and surface roughness. Moreover, the elemental distribution of nitrogen on the machined surface was qualitatively determined by EPMA to assess the effects on surface modification. Micro hardness and wear resistance tests were performed to evaluate the effects of the reinforced surface. Experimental results indicate that the nitrogen element decomposed from the dielectric that contained urea, migrated to the work piece, forming a TiN hard layer, resulting in good wear resistance of the machined surface after EDM.