An Investigation into enhancement of surface finish of electrochemically machined surface

Abstract

Challenge posed by ever-growing demand for reliable products under dynamic conditions evolved families of different advanced materials namely stainless steel, high carbon high chromium die steel, hast alloy and super alloys, that are difficult to machine. These materials predominately play vital role in advanced manufacturing industries i.e., aerospace, defense and automobiles. Since 1940s, several attempts were made to circumvent the problems related to machining of advanced materials. Traditional machining methods were replaced by non-traditional machining techniques that developed various advanced machining processes i.e., Ultrasonic machining (USM), Abrasive jet machining (AJM), water jet machining (WJM), Electrical discharge machining (EDM), Laser beam machining (LBM), Electron beam machining (EBM) and Electrochemical machining (ECM). Where in material is removed by mechanical means, thermal and anodic dissolution as applicable respectively. Also hybrid machining processes such as ECM with ultrasonic vibration (ECM-UV), ECM with EDM processes were developed. Advanced machining process such as ECM is used extensively in aerospace industry for machining turbine blades made of super alloy and small cooling holes of high aspect ratio. There is lack of information about enhancement of quality of hole (Surface roughness, overcut) by traditional ECM. These studies are restricted to i) parameter selection, ii) selection of combination of work piece /tool and electrolyte. iii) Tool design and anodic profile prediction newlineLiterature review shows that there is sub-stained gain in machining accuracy owing to uniform flow of electrolyte in the machining gap. The given study focuses on the development of Pulse current shaped tube electrochemical machining (PC-STED) process by using rotary electrode movement. The feasibility of proposed method is experimentally verified. Attempts are being made to investigate optimum process parameters such as Voltage, feed rate, Pulse on time; Duty cycle, pressure and tool rotation etc.