Optimization of Electrochemical Micro Machining Parameters for Nickel Based Alloys

Abstract

In recent years, the engineering landscape has needed components and devices in Aeronautical, automobile, medical, heat exchangers, electronics, chemical and food processing Industries, increasing daily. This research study investigated nickel 201 and Inconel 600 alloys using a chemical machining process. However, it is challenging to machine due to its high strength, excellent mechanical strength, no heat-affected zone in the machining surface, good corrosion resistance, high-temperature stability and poor thermal diffusion. Conventional machining methods for these materials may result in decreased lifetime. Electrochemical micromachining is an advanced, non-traditional technique which is suitable for machining hard materials, strenuous materials and Intricate shapes. However, machining hard metals like nickel alloys is challenging compared to conventional methods of drilling. Other micromachining techniques like electro-discharge machining, laser beam drilling, and plasma drilling generate mechanical force and friction, leading to rapid tool wear, residual stress, low material removal rate and thermal distortion. Among various non-traditional techniques, electrochemical micromachining is more suitable due to its higher material removal rate, good surface quality and accuracy.The ECMM process works similarly to reverse electroplating, based on Faraday s Law of Electrolysis. In this study, sodium nitrate and hydrochloric acid were used as the electrolytes between the workpiece and the micro tool. DC pulsed power supply was used to remove the material from the workpiece at the microscopic level. In this experimental study, 0.15 x 0.25 x 50 mm Nickel 201 and Inconel 600 sheets were used. This study investigates the effect of various input process parameters, including voltage, current, duty cycle, electrolyte concentration, and frequency. Taguchi s L18 orthogonal array method was used in these experiments to identify the most influential process parameters affecting machining performance.