A STUDY ON ELECTROCHEMICAL MICROMACHINING OF SUPER DUPLEX STAINLESS STEEL FOR BIOMEDICAL FILTERS

In recent days, industries are looking for miniature components which can perform complex functions in the areas of electronics, biomedical and nuclear applications. Electrochemical micromachining (ECMM) is an emerging nonconventional technology for producing micro/meso scale components. The micromachining of super duplex stainless steel (SDSS) is generally very difficult, less accurate and time consuming when using many of the nonconventional machining methods. By the use of ECMM the above limitations can be overcome. In this paper, an experimental investigation is carried out to identify the optimal machining parameters for machining SDSS using ECMM. Experiments are conducted based on Taguchi L18 orthogonal array to find the influencing machining parameters on Material Removal Rate (MRR). Statistical analysis of variance is performed to determine the percentage contribution of individual process parameters on MRR. Among the various factors investigated, duty cycle is found to be the most significant factor and contributes about 42% to the MRR. As the duty cycle increases, the pulse on time also increases which contributes to more MRR. The parameters such as current 0.6 amps, voltage 9V, frequency 30 Hz, electrolyte concentration 0.5 mol/lit and duty cycle 66.66% produce maximum MRR in the micromachining of SDSS. This research helps to understand the selection of the machining parameters for ECMM of SDSS.