Influence of Pulse Period and Duty Ratio on Electrochemical Micro Machining (EMM) Characteristics
Malapati Manoj Kumar Reddy
Issue:
Volume 1, Issue 4, October 2013
Pages:
78-86
Received:
3 March 2013
Published:
20 September 2013
Abstract: Electrochemical Micro Machining (EMM) appears to be promising as a future micro machining technique since in many areas of applications; it offers several advantages including electronic, biomedical and MEMS/NEMS applications. Electrochemical Machining (ECM) can be effectively used in the micron range by maintaining very smaller inter electrode gap with proper controlling of predominant micromachining parameters during machining. Present paper will highlight the influence of various EMM process parameters i.e. machining voltage, electrolyte concentration, pulse period and duty cycle ratio on machining performance criteria e.g. material removal rate and machining accuracy to meet the micro machining requirements. Some of the experiments had been carried out on copper to investigate the most effective zone, which gives high machining accuracy with appreciable amount of material removal rate and optimum machining speed. From the experimental results, it has been observed that the introduction of short pulse period improves EMM performance characteristics. Attempt has also been made to study and compare the surface condition of the machined micro holes through SEM micrographs. From the analysis of test results and SEM micrographs it can be observed that optimum value of machining voltage is about 3V, pulse period is about 200 μsec, duty cycle ratio is about 20% and electrolyte concentration is about 20 g/l which will produce accurate micro holes with highest possible amount of material removal.
Abstract: Electrochemical Micro Machining (EMM) appears to be promising as a future micro machining technique since in many areas of applications; it offers several advantages including electronic, biomedical and MEMS/NEMS applications. Electrochemical Machining (ECM) can be effectively used in the micron range by maintaining very smaller inter electrode gap...
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Study of Residual Stresses from Two Machining Protocols Using an Indentation Method
Felipe V. Díaz,
Claudio A. Mammana,
Armando P. Guidobono
Issue:
Volume 1, Issue 4, October 2013
Pages:
87-92
Received:
19 August 2013
Published:
30 September 2013
Abstract: Although high-speed machining offers a number of advantages over conventional machining, it is possible that the residual stress distributions generated by the former can affect the service life of the processed components. In this paper, a newly developed micro-indent method is used to evaluate different residual stress states, which were introduced in samples of AA 7075-T6 aluminum alloy milled at low and high-speed. Different surfaces were generated by varying the cutting speed in one order of magnitude, from 100 m/min to 1000 m/min. Two machining protocols, which consist of using different machine tools, were evaluated. The results show that it is possible to generate and to evaluate very small residual stresses. Finally, the values and levels obtained for normal components were analyzed in function of mechanical and thermal effects that generated the residual stresses.
Abstract: Although high-speed machining offers a number of advantages over conventional machining, it is possible that the residual stress distributions generated by the former can affect the service life of the processed components. In this paper, a newly developed micro-indent method is used to evaluate different residual stress states, which were introduc...
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