SFRF-2014

Mr. Mayank Srivastava, Assistant Professor, Department of Mechanical Engineering attended the Summer Faculty Research Fellow Programme (SFRF-2014) under Quality Improvement Programme: Continuing Education Programme (QIP/CEP) held at India Institute of Technology, Delhi (IITD) during the period 15th May - 16th July, 2014. He worked under the supervision of Prof. P. Venkateshwara Rao (Department of Mechanical Engineering) in his area of interest i.e. Non-Traditional Machining.

CEP has taken a new initiative of starting Summer Faculty Research Fellow Programme since 2008. The SFRF-2014 was attended by more than 100 participants from across various reputed colleges all over the country. The objective of this programme is to help in inducting and inculcating research culture among the faculties of various engineering institutes outside the IIT system. The faculty fellow also gets an opportunity to interact and work with the faculty and research students of the group and also gets the exposure to the equipment and lab facilities available at IIT Delhi.

Mr. Mayank Srivastava studied the research papers regarding the machining of non-conducting materials and he identified the area to conduct his research work. He then worked on determining the effects of various input parameters like power, current, voltage, etc. on MRR (Material Removal Rate), TWR (Tool Wear Rate) and SR (Surface Roughness) on electrically non-conducting material surface using EDM (Electric Discharge Machining). Electric discharge machining (EDM) has been proven as an alternate process for machining complex and intricate shapes from the conductive ceramic composites. EDM is always been used for machining of conducting workpieces. Although there is no work had been done till now regarding the machining of non-conducting workpieces using EDM Machining. The main examples of non-conducting workpieces are Silicon Carbide (SiC), Zirconium Oxide (ZiO2), and many more. Therefore, to apply EDM for machining nonconductive ceramic materials, a basic technique is developed in which a conductive metallic layer is applied on the surface of the workpiece. This additional conductive metallic layer is referred as assisting electrode (AE).

The initial electrical sparks occur in the machining gap between the tool electrode and the assisting conductive electrode. In this method, kerosene is used as dielectric fluid. After the finishing of AE layer, carbon particles are cracked due to the disassociation of kerosene molecule. This carbonic layer provides the essential electrical conductivity to progress the process. Adhesive copper or aluminium foil, coating of graphite or carbon, silver varnish and copper, silver or gold sputtered on the workpiece surface can be used as AE. In EDM of conductive materials, material is removed mostly by melting and evaporation, but the main material removal mechanism in EDM of nonconductive ceramics is spalling which occurs due to the alternating thermal load of the electrical sparks. Thus material removal is influenced greatly by the input energy level.