An intelligent and automated system for EDM hole drilling of super alloys
This paper introduces an intelligent and automated system proposed for EDM hole drilling of super-alloys in manufacturing and re-manufacturing stages of products used in aerospace, die/mold and medical surgery. The system is a user-friendly computer-based program, which guides the end-user in order to perform sustainable and effective process. To accomplish the goals of the work, a well-planned workshop tests have been performed via drilling of micro and macro-scale holes (0.4-3 mm) on Ti-6AI-4V and Inconel 718 alloys, which are commonly used in aerospace industry and medical sector for manufacturing of highly critical components. The experimental data was refined and analysed using ANOVA to obtain parameter's relations and mathematical modelling for optimisation. ANFIS has been adopted to correlate the EDM hole drilling parameters (i.e. pulse current, pulse duration/interval, capacitance, material removal rate, electrode wear and surface roughness) for fulfilling reliable, cost/time effective and efficient hole making operations.
Small hole drilling in EDM
Abstract Among the numerous applications of electrical discharge machining (EDM) in industry, drilling of fairly small holes (0.75–2.0 mm) in hard-to-machine alloys (e.g. high speed steel) and small holes ( The results were correlated to give a formula for overcut in terms of discharge voltage, circuit capacitance, diameter of the tool and the depth of the hole. Another correlation was obtained between the taper in the hole produced and the diameter of the tool and the depth of the hole.
Athenian Democracy at War
Classical Athens perfected direct democracy. The plays of this ancient Greek state are still staged today. These achievements are rightly revered. Less well known is the other side of this success story. Democratic Athens completely transformed warfare and became a superpower. The Athenian armed forces were unmatched in size and professionalism. This book explores the major reasons behind this military success. It shows how democracy helped the Athenians to be better soldiers. For the first time David M. Pritchard studies, together, all four branches of the armed forces. He focuses on the background of those who fought Athens' wars and on what they thought about doing so. His book reveals the common practices that Athens used right across the armed forces and shows how Athens' pro-war culture had a big impact on civilian life. The book puts the study of Athenian democracy at war on an entirely new footing.