POSTER PAPER International Journal of Recent Trends in Engineering, Vol. 1, No. 5, May 2009 100 A Review on Current Research Trends in Die- Sinking Electrical Discharge Machining of Conductive Ceramics Ms. Shruti Mehta 1 , Mr. Avadhoot Rajurkar 2 , Mr. Jignesh Chauhan 3 1,2,3 Department of Mechanical Engineering, Charotar Institute of Technology, Education Campus – Changa Ta. Petlad Dist. Anand, GUJARAT, INDIA 1. shruti18xx@yahoo.co.in, 2. a4u2002@gmail.com Abstract—In recent years, incessant research in material science has encouraged the engineering and development of advanced ceramic materials. Such materials satisfy the needs of high end applications in the areas of aerospace, automotive, defense, biological and nuclear fields. Whereas, due to inherent capability of machining of any conductive material irrespective of its hardness and strength, Electrical Discharge machining process has been the potential choice for machining of such novel materials. Simultaneously, it also achieves comparatively high removal rates. Various researchers have made their significant contributions, exploring the potential applicability of the process in this domain. Majority of work concentrates on improvement in process efficiency, optimization of process variables and process monitoring and control. Noteworthy efforts had been applied to reveal the effect of electrical and non-electrical parameters on response parameters for various electrode- workpiece material combinations. Oxides, non-oxides and composites in conductive form have been the principle choices of researchers. This paper abruptly reviews the development of conductive ceramic materials followed by the progress of EDM technology in this context from its initiation to present state. The discussion is extended to key research areas such as optimizing the material removal, monitoring electrode wear, effect on surface quality. The present and prospering application ranges of such materials are also accounted for. Index Terms— die-sinking EDM, conductive ceramics, material removal rate, electrode wear. I. INTRODUCTION The latest improvements in properties of ceramics have led to the development of high strength and high toughness ceramic composites. Non-conventional techniques such as Ultrasonic machining, Laser Beam machining and Electro Discharge machining (EDM) are proving their competitiveness over conventional machining methods for machining of such novel materials. [6,8] Out of these, EDM is a reproductive shaping process in which the form of the tool electrode is mirrored onto the workpiece. The material is removed by a series of repeated electrical discharges between the tool (called electrode) and the part being machined in presence of a dielectric fluid. Its unique feature of using thermal energy to machine electrically conductive parts regardless of hardness has been its distinct advantage in the manufacture of mould, die, automotive, aerospace and surgical components. [1,5,20] In line with current knowledge, the main inconvenience when applying the EDM technology to the field of ceramic materials is the electrical resistivity of these materials, which usually lies between 100 and 300Ωcm [6,22,23]. However this difficulty could be overcome by doping with conductive elements and incorporating impurities into ceramics. With technological progress, a wide range of advanced ceramic materials are available for machining. [23] The review presented in this paper covers the study of contributions made by various researchers to enhance the development and applications of ceramic materials. II. CERAMICS Since last three decades or so, with the advances of understanding in ceramic chemistry, crystallography and the more extensive knowledge gained in regard to the production of advanced and engineered ceramics, that the potential for these materials has been realised. One of the major developments in this century is the work by Ron Garvie et. al. at the CSIRO, Melbourne where PSZ (partially stabilised zirconia) and phase transformation toughening of this ceramic was developed. This advancement changed the way ceramic systems were viewed. Techniques previously applied to metals are now considered applicable to ceramic systems. Phase transformations, alloying, quenching and tempering techniques are applied to a range of ceramic systems. Significant improvements to the fracture toughness, ductility and impact resistance of ceramics are being realised and thus the gap in physical properties between ceramics and metals began to close. More recent developments in non-oxide and tougher ceramics (e.g. nitride ceramics) have closed the gap even further [2]. A. Advanced Ceramic Materials The term, technical advanced ceramic materials, is a relatively new term applied to a range of various materials generally obtained from inorganic primary materials with a high grade of purity. These primary materials are subjected to typical processes in powder metallurgy and afterwards, to high temperature sintering processes. With these materials, it is possible to obtain high-density parts, which have good technical properties © 2009 ACADEMY PUBLISHER