Effect of Duty Ratio at Different Pulse Frequency during Hole Drilling in Ceramics Using Electrochemical Discharge MachiningPankaj Kumar Gupta, Jai Prakash Bhamu, Chandra Shekhar Rajoria, Nitin Kumar Lautre and Vishnu AgarwalMATEC Web Conf., 77 (2016) 10004DOI: https://doi.org/10.1051/matecconf/20167710004