An Experimental Investigation of Surface Characterization for Zirconia Ceramic Using Electrochemical Discharge Machining Process

The industrial acceptance of ceramic materials is gradually increasing because of their attractive properties such as high strength, hot hardness, biocompatibility, insulating, and chemical stability over monolithic materials. The Zirconia (ZrO₂) is a ceramic material of nonconductive and brittle in nature; thereby, it is very difficult to machine by very popular well-known machining methods like ECM, WEDM, EDM, etc. The machining problem resists its industrial applications. To overcome this problem, electrochemical discharge machining (ECDM) is a combination of electrochemical and electrical discharge machining methods used to machine the nonconductive ZrO₂ material. The effects of machining parameters on machining responses were analysed through different graphs. Taguchi method-based L₁₆ (4⁵) orthogonal array was employed and utilized the acquired results to optimize the machining parameters. The experimental results reveal that the DC supply voltage and electrolyte concentration are the main governing factors in controlling the machining performance. The better material removal rate was identified at 65 V, 16 g/l electrolyte concentration, and 60-mm inter-electrode gap. FESEM images identified some of the micro-cracks on the machined hole surface when machining operations were carried out at a higher level of parameter setting. The presence of iron (Fe) was identified from EDS analysis, and it may be due to the diffused part of the steel cathode adhering to the machined surface.