Experimental investigation on micro-electrochemical sinking operation for fabrication of micro-holes

Based on the principle of confined electrochemical dissolution of anode material with short voltage pulses, the machining of micro-holes by micro-electrochemical sinking operation has been investigated through a setup developed in-house. This paper describes the related problems and the solutions for the process of machining micro-holes on 304 SS sheet of 50 mu m thickness using high-speed steel cylindrical tool of diameter 500 mu m and using dilute H2SO4 as electrolyte. The variation of the taper angle of the drilled holes with different experimental parameters setting has been analyzed and reported. Very stable machining has been observed while machining with the variation of T-on and at the parameter setting of 7 V, 500 kHz and 0.1 M. The minimum value of radial overcuts (38 mu m at hole entry and 28 mu m at hole exit) and minimum value of taper angle (8 degrees) of the machined hole have been observed at parameter setting of 500 kHz, 10 V, 700 nS, 0.1 M.