INVESTIGATIONS ON TANDEM MICRO-EDM AND MICROECM PROCESSES

Abstract

Today's technological advancement necessitates the miniaturisation of components without sacrificing efficiency. In modern engineering applications, size variation has been shifting from the macro to the micro level. However, machining and finishing such components is the major challenge for the manufacturing industry. Besides, advances in metallurgy, such as introducing "difficult-to-machine" materials like titanium and nickel and their alloys, raise the stakes for the micromachining industry. These materials exhibit excellent corrosion resistance even at elevated temperatures. Hence, finding widespread applications in high-value and technologically advanced manufacturing industries, such as aerospace, micro-electromechanical systems (MEMS), biomedical, automotive, mould and die, and precision consumer goods. Materials classified as "difficult-to-machine" present considerable difficulties like high tool wear rate, low dimensional accuracy, and poor surface integrity when micromachined using conventional methods. As a result, unconventional micromachining methods are often used. Electro-discharge micromachining (EDM) and electrochemical micromachining (ECM) processes can machine electrically conductive materials irrespective of their mechanical properties. However, the pervasive demands for miniaturized components made from "difficultto- machine" corrosion-resistant materials having tighter dimensional tolerances and superior surface integrity have challenged the process capability of EDM and ECM. Every process offers a unique set of advantages and shortcomings. No single existing process can machine a miniature component with all the desired attributes. Some processes can yield tighter dimensional accuracy while sacrificing surface integrity, or vice versa.