Production of Micro-holes on Duplex Stainless Steel 2205 by Electrochemical Micromachining: A Grey-RSM Approach

Abstract

Electrochemical micromachining (ECMM) is a non-traditional micro-fabrication technology developed to produce complex geometries on very hard and electrically conducting surfaces. Typical applications of ECMM include aerospace components, medical devices and gas turbine blades. Duplex stainless steel 2205 (DSS 2205) is an exceptional corrosion-resistant iron alloy with a nearly identical volume of austenite and ferrite. In the present work, ECMM was employed to produce a series of through micro-holes on DSS 2205 sheet. Brass and copper tungsten alloys were used as two separate electrode materials for micro-hole making experimentations. Micro-hole making experimental trials were executed using L27 orthogonal array. The collective methods of grey-based response surface methodology and analysis of variance were attempted to recognize the critical variables influencing the output parameters. The impact of machining variables on material removal rate, surface roughness and overcut was investigated through response surface plots. The optimal parameter settings were validated by performing a confirmation test. Morphologies of the machined micro-holes were analysed by scanning electron microscopic images. 3D surface measurement tester was used to estimate the roughness of the surface adjacent to the micromachined holes.