Plasma Temperature and Electron Density of Dry µ-EDM on Stainless Steel and Silicon: A Comparison
Kanmani Subbu Subbian*, Ramkumar Janakarajan*,
and Dhamodaran Santhanagopalan**
*Department of Mechanical Engineering, Indian Institute of Technology Kanpur, Uttar Pradesh, Kanpur, India
**Department of Physics, Indian Institute of Technology Kanpur, Uttar Pradesh, Kanpur, India
Fabricating micro/nano-features in devices and largescale production with short lead times is challenging, and many individual and hybrid processes have been developed to meet this challenge. Among nonconventional processes, micro-electric discharge machining (µ-EDM) has many advantages due to the possibility of precise and accurate 2D and 3D machining of complex shapes. Dry µ-EDM is used to process assembled or semi-assembled products. Attempts are being made to improve the µ-EDM process, and further improvement is possible through better understanding the role of discharge plasma in the machining process. We studied plasma and crater characteristics during dry µ-EDM, calculating plasma parameters for different discharge energies using optical emission spectroscopy. Line pair method and modified Saha equations are used to calculate plasma temperature and electron density respectively. Craters were morphologically analyzed using scanning electron microscopy (SEM), and plasma and crater characteristics on stainless steel and silicon were compared.
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