Manufacturing Technology Today

J. Prasanna ¹, P. Mannar Jawahar ², B. Mohan ³

Affiliations
1 Dept. of Mechanical Engineering, College of Engineering, Anna University, Chennai-600025, IN
2 Centre for University, Industry Collaboration, Anna University, Chennai-600025, IN
3 Dept. of Production Technology, Madras Institute of Technology, Anna University, Chennai-600044, IN

Abstract

Material removal in the electrical discharge machining (EDM) is primarily due to a thermal mechanism. Therefore, the analysis of plasma in EDM is a crucial one to realize the concept of the machining. This work looks into the temperature measurement of the EDM plasma by using a newly designed optical system. The measuring system consists of an optical fiber positioned in the dielectric oil and spectrometers interfaced with charge coupled devices (CCDs). Spectral data of the plasma spark was analyzed by means of image-processing technique in-turn to measure the relative intensities of Fe I spectral lines emitted during the machining. The outcome of this study reveals that the temperature of the EDM plasma varies from 7965° K to 9680° K for a significant range of gap current.

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D. Sathianarayanan ¹, L. Karunamoorthy ², G. S. Kandasami ³, B. Mohan ¹

Affiliations
1 Department of Production Technology, M.l.T. Campus, Anna University, Chennai, 600 044, IN
2 Department of Mechanical Engineering, CEG Campus, Anna University, Chennai, 600 025, IN
3 Jaya Engineering College, Tiruninravur, Chennai, IN

Abstract

Chatter develops easily during boring operation on a lathe because of low stiffness and damping of the system. The most important parameter is damping associated with the cutting process, which is related to cutting conditions. In this paper a method of utilizing the magnetorheological fluid’s non-linear vibration characteristics for increasing the cutting stability is proposed. The designed damper is a semi-actively controllable fluid damper, which improves cutting stability and suppresses the chatter vibrations. The damper employs a magnetorheological fluid that changes its rheological properties in the presence of a magnetic field. Varying the current flow through the magnetic coil can vary the damping force developed by the magnetorheological fluid damper. The results show that for a particular cutting condition a particular value of magnetic coil current is more effective in chatter suppression.

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