The Experts below are selected from a list of 99 Experts worldwide ranked by ideXlab platform

J.m. Bisang - One of the best experts on this subject based on the ideXlab platform.

  • Mass-transfer studies in an electrochemical reactor with a Small Interelectrode Gap
    Electrochimica Acta, 2013
    Co-Authors: Alejandro Nicolás Colli, R. Toelzer, M. E. H. Bergmann, J.m. Bisang
    Abstract:

    Abstract This paper reports the distribution of the local mass-transfer coefficient along the electrode length for an electrochemical reactor with parallel-plate electrodes and narrow Interelectrode Gaps of 1 and 2.2 mm, using the reduction of ferricyanide as a test reaction. The studies were performed at different flow rates, Reynolds numbers ranging from 370 to 3700, with the empty reactor and also the Interelectrode Gap was filled with two types of expanded plastics and a woven plastic mesh as turbulence promoters. The effect of both the Interelectrode Gap and the partial placing of the turbulence promoter along the electrode length on the mass-transfer behaviour was also analyzed. In all cases the pressure drop across the reactor was measured. A more uniform distribution of the local mass-transfer coefficient, ±15% related to its mean value, and an important increase of the mean mass-transfer coefficient, enhancement factor ranging from 2 to 8, were observed, depending on the type of turbulence promoter, the volumetric flow rate, and the Interelectrode Gap.

A Sarkar - One of the best experts on this subject based on the ideXlab platform.

  • influence of tool vibration on machining performance in electrochemical micro machining of copper
    International Journal of Machine Tools & Manufacture, 2007
    Co-Authors: B Bhattacharyya, M Malapati, J Munda, A Sarkar
    Abstract:

    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 biomedical and MEMS applications. A suitable micro-tool vibration system has been developed, which consists of tool-holding unit, micro-tool vibrating unit, etc. The developed system was used successfully to control material removal rate (MRR) and machining accuracy to meet the micro-machining requirements. Micro-holes have been produced on thin copper workpiece by EMM with stainless-steel micro-tool. Experiments have been carried out to investigate the most effective values of process parameters such as micro-tool vibration frequency, amplitude and electrolyte concentration for producing micro-hole with high accuracy and appreciable amount of MRR. From the experimental results and SEM micrographs, it is evident that the introduction of micro-tool vibration improves EMM performance characteristics. Lower electrolyte concentration in the range of 15–20 g/l reduces stray current effects. Hertz (Hz) range of tool vibration frequency improves the removal of sludge and precipitates from very Small Interelectrode Gap. The 150–200 Hz range of tool vibration frequency can be recommended for EMM, which provides a better electrochemical machining in the narrow end Gap. Compared to kHz range, Hz range micro-tool's vibration improves the MRR and accuracy in EMM.

V V Lyubimov - One of the best experts on this subject based on the ideXlab platform.

  • the scanning dimensional microelectrochemical machining with the ultra Small Interelectrode Gap
    Procedia CIRP, 2016
    Co-Authors: V V Lyubimov, V M Volgin, I V Gnidina, Vladislav Krasilnikov
    Abstract:

    Abstract The process of the micro electrochemical machining with the ultra Small Interelectrode Gap without the electrode-tool displacement for the flushing with the workpiece scanning by the electrode-tool and with F et /F wp = 0.5 – 25% is considered in the publication. The modeling of the MECM process at the various electrode-tool paths on X- and Y-axes with periodic updating of the UIEG on Z-axis during the anode dissolution of the workpiece is executed.

  • Theoretical analysis of micro/nano electrochemical machining with ultra-short voltage pulses
    Electrochimica Acta, 1
    Co-Authors: Vladimir M. Volgin, V V Lyubimov, T.b. Kabanova, Alexey D. Davydov
    Abstract:

    Abstract The effect of pulse-on and pulse-off times on the efficiency of micro/nano ECM with ultra-short voltage pulses is theoretically analyzed. A new approximate analytical equation for the time of charging electrical double layer (EDL) is obtained. The equation takes into account all main parameters of the process. It enables one to determine the pulse-on time that provides a high localization of Faradaic process in the zones with Small Interelectrode Gap and a high productivity of ECM process. The results of numerical calculations agree well with the data calculated by the proposed approximate analytical equation. The numerical calculations of the pulse-off time are performed. The effect of reverse voltage pulse imposed in the pauses on the EDL relaxation time is analyzed. The amplitude of reverse voltage pulse is limited by the condition of the absence of the tool-electrode wear. The proposed algorithm for calculating the pulse-off time and amplitude of reverse voltage pulse provides the required high coefficient of metal dissolution localization in the zone of Small Interelectrode Gaps at a given pulse-on time.

Alejandro Nicolás Colli - One of the best experts on this subject based on the ideXlab platform.

  • Mass-transfer studies in an electrochemical reactor with a Small Interelectrode Gap
    Electrochimica Acta, 2013
    Co-Authors: Alejandro Nicolás Colli, R. Toelzer, M. E. H. Bergmann, J.m. Bisang
    Abstract:

    Abstract This paper reports the distribution of the local mass-transfer coefficient along the electrode length for an electrochemical reactor with parallel-plate electrodes and narrow Interelectrode Gaps of 1 and 2.2 mm, using the reduction of ferricyanide as a test reaction. The studies were performed at different flow rates, Reynolds numbers ranging from 370 to 3700, with the empty reactor and also the Interelectrode Gap was filled with two types of expanded plastics and a woven plastic mesh as turbulence promoters. The effect of both the Interelectrode Gap and the partial placing of the turbulence promoter along the electrode length on the mass-transfer behaviour was also analyzed. In all cases the pressure drop across the reactor was measured. A more uniform distribution of the local mass-transfer coefficient, ±15% related to its mean value, and an important increase of the mean mass-transfer coefficient, enhancement factor ranging from 2 to 8, were observed, depending on the type of turbulence promoter, the volumetric flow rate, and the Interelectrode Gap.

B Bhattacharyya - One of the best experts on this subject based on the ideXlab platform.

  • influence of tool vibration on machining performance in electrochemical micro machining of copper
    International Journal of Machine Tools & Manufacture, 2007
    Co-Authors: B Bhattacharyya, M Malapati, J Munda, A Sarkar
    Abstract:

    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 biomedical and MEMS applications. A suitable micro-tool vibration system has been developed, which consists of tool-holding unit, micro-tool vibrating unit, etc. The developed system was used successfully to control material removal rate (MRR) and machining accuracy to meet the micro-machining requirements. Micro-holes have been produced on thin copper workpiece by EMM with stainless-steel micro-tool. Experiments have been carried out to investigate the most effective values of process parameters such as micro-tool vibration frequency, amplitude and electrolyte concentration for producing micro-hole with high accuracy and appreciable amount of MRR. From the experimental results and SEM micrographs, it is evident that the introduction of micro-tool vibration improves EMM performance characteristics. Lower electrolyte concentration in the range of 15–20 g/l reduces stray current effects. Hertz (Hz) range of tool vibration frequency improves the removal of sludge and precipitates from very Small Interelectrode Gap. The 150–200 Hz range of tool vibration frequency can be recommended for EMM, which provides a better electrochemical machining in the narrow end Gap. Compared to kHz range, Hz range micro-tool's vibration improves the MRR and accuracy in EMM.