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The purpose of this study is to explore the machining characteristics of electrical discharge machining (EDM) when a tool is fabricated using powder metallurgy. Because pure Cu tools obtained using conventional machining pose problems of high tool wear rate, tool oxidation causes loss of characteristics in tool shape.

The research investigation carried out experiments planned through Taguchi’s robust design of experiments and used analysis of variance (ANOVA) to carry out statistical analysis.

It has been found that copper and chromium electrodes give less metal removal rate as compared to the pure Cu tool. Analytical outcomes of ANOVA demonstrated that MRR is notably affected by the variable’s polarity, peak current, pulse on time and electrode type in the machining of EN9 steel with EDM, whereas the variables pulse on time, gap voltage and electrode type have a significant influence on EWR. Furthermore, the process also showed that the use of powder metallurgy tool effectively reduces the value of SR of the machined surface as well as the tool wear rate. The investigation exhibited the possibility of the use of powder metallurgy electrodes to upgrade the machining efficiency of EDM process.

There is no major limitation or implication of this study. However, the composition of the powders used in powder metallurgy for the fabrication of tools needs to be precisely controlled with careful control of process variables during subsequent fabrication of electrodes.

To the best of the authors’ knowledge, this is the first study that investigates the effectiveness of copper and chromium electrodes/tools fabricated by means of powder metallurgy in EDM of EN9 steel. The effectiveness of the tool is assessed in terms of productivity, as well as accuracy measures of MRR and surface roughness of the components in EDM machining.

During a press conference at the Imperial Hotel in Delhi on 13 March 2001, the Internet news site, Tehelka.com, showed secret video footage of senior politicians, bureaucrats, and army officers accepting money in a fake defense deal. Two journalists from Tehelka, Anirudha Bahal and Mathew Samuel, posed as arms dealers from a fictitious arms company called West End International to sell nonexistent handheld thermal cameras to senior officials of the Ministry of Defense (MOD) in India. Bahal and Samuel paid bribes to politicians, civil servants, and army officers to procure government contracts. The journalists used three hidden cameras to videotape the corrupt politicians and officials accepting the bribes, with the most dramatic video clip showing the Bharatiya Janata Party (BJP) President, Bangaru Laxman, accepting a wad of currency notes from them. Laxman later claimed that he was not guilty of wrongdoing for accepting Rs. 100,000 (US$2,170) as a donation for the BJP. Describing the episode as “concocted,” he added that he had given the donation to the BJP's treasurer (BBC News, 2001a).