Experimental Investigation of the Effects of Electrode Shape on ECSM Performance during Machining of Alumina Ceramics

Advanced ceramic material like alumina ceramic is continuously gaining the industrial acceptance in various applications such as cutting tools, electrical and thermal insulators, turbine blades, electronic devices etc. due to the superior properties of such ceramic. The alumina ceramic has different superior qualities such as high hardness, refractoriness, wear and corrosion resistance, high temperature withstands capability, low thermal coefficient of expansion etc. But machining of alumina ceramics is very difficult because of its brittleness and electrically nonconductive. Keeping in view, the present research work undertakes the machining study through design and fabrication of electrochemical spark machining (ECSM) setup. Experiments were carried out with three different shapes of electrodes such as (i) solid circular shape of 0.8mm diameter (ii) hollow circular shape of 0.8mm external and 0.6mm internal diameter (iii) 0.8mm diameter solid circular tool with flutes i.e. drill type electrodes. The experimental results and SEM images of the machined holes revealed that the solid circular drill electrode is better electrode as compared to the others electrodes used for experiments for machining of hole on alumina ceramic workpiece specimens. The working range of different machining parameters was also identified on the basis of experimental results and analyzed the effects of ECSM set-up parameters on response characteristics.