Anodic dissolution of electrochemical chromium coatings in electrolytes for electrochemical machining: The dissolution rate and surface roughness

2010 ◽  
Vol 46 (1) ◽  
pp. 1-8 ◽  
Author(s):  
S. A. Silkin ◽  
V. I. Petrenko ◽  
A. I. Dikusar
Keyword(s):  
Surface Roughness ◽  
Dissolution Rate ◽  
Anodic Dissolution ◽  
Electrochemical Machining

Modeling the Interactions of Hydrogen, Stress and Dissolution in Near-Neutral pH Stress Corrosion Cracking of Pipelines

2006 ◽  
Author(s):  
Frank Y. Cheng
Keyword(s):  
Stress Corrosion ◽  
Dissolution Rate ◽  
Crack Growth ◽  
Anodic Dissolution ◽  
Hydrogen Concentration ◽  
Stress Corrosion Cracking ◽  
Crack Tip ◽  
Corrosion Cracking ◽  
Neutral Ph ◽  
Ph Stress

A thermodynamic model was developed to determine the interactions of hydrogen, stress and anodic dissolution at the crack-tip during near-neutral pH stress corrosion cracking in pipelines. By analyzing the free-energy of the steel in the presence and absence of hydrogen and stress, it is demonstrated that a synergism of hydrogen and stress promotes the cracking of the steel. The enhanced hydrogen concentration in the stressed steel significantly accelerates the crack growth. The quantitative prediction of the crack growth rate in near-neutral pH environment is based on the determination of the effect of hydrogen on the anodic dissolution rate in the absence of stress, the effect of stress on the anodic dissolution rate in the absence of hydrogen, the synergistic effect of hydrogen and stress on the anodic dissolution rate at the crack-tip and the effect of the variation of hydrogen concentration on the anodic dissolution rate.

scholarly journals An Investigation of Milling using a Combination of Electrical Discharge (ED) and Electrochemical (EC) Machining Techniques

2021 ◽  
Vol 9 (VI) ◽  
pp. 3657-3661
Author(s):  
Vishal Gandhi
Keyword(s):  
Surface Roughness ◽  
Anodic Dissolution ◽  
Surface Finish ◽  
Single Machine ◽  
Electrical Discharge ◽  
Spark Erosion

This study investigate the machining operation perform by the combination of EDM and ECM process. Since in case of EDM the surface finish obtain is not as good as required so next machining operation is done by ECM. As we have, in EDM metal is removed from the workpiece through spark erosion and in ECM metal removed by anodic dissolution in the electrolyte. Both the process is done simultaneously in single machine changing the potential on anode and cathode and the medium. The EDM surface of 1μ mm Ra is improved to 0.2μ mm Ra by applying ECM. The surface roughness of a machined hole is improved to 0.07 mm Ra by applying 2 min of ECM lapping. Both the process is done simultaneously.

scholarly journals Experimental Research on Discharge Forming Cutting-Electrochemical Machining of Single-Crystal Silicon

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Bin Xin ◽  
Wei Liu
Keyword(s):  
Surface Roughness ◽  
Single Crystal ◽  
Electrical Discharge ◽  
Electrical Discharge Machining ◽  
Electrochemical Machining ◽  
Single Crystal Silicon ◽  
Recast Layer ◽  
Movement Speed ◽  
Crystal Silicon ◽  
Wedm Process

During the wire electrical discharge machining (WEDM) process, a large number of discharge pits and a recast layer are easily generated on the workpiece surface, resulting in high surface roughness. A discharge forming cutting-electrochemical machining method for fabricating single-crystal silicon is proposed in this study to solve this problem. On the same processing equipment, single-crystal silicon is first cut using the discharge forming cutting method. Second, electrochemical anodic reaction technology is used to dissolve the discharge pits and recast layer on the single-crystal silicon surface. The machining mechanism of this process, the surface elements of the processed single-crystal silicon and a comparison of the kerf width are analyzed through experiments. On this basis, the influence of the movement speed of the copper foil electrode during electrochemical anodic dissolution on the final surface roughness is qualitatively analyzed. The experimental results show that discharge forming cutting-electrochemical machining can effectively eliminate the electrical discharge pits and recast layer, which are caused by electric discharge cutting, on the surface of single-crystal silicon, thereby reducing the surface roughness of the workpiece.

Comparison of the electrochemical machinability of electron beam melted and casted gamma titanium aluminide TNB-V5

2017 ◽  
Vol 232 (4) ◽  
pp. 586-592 ◽  
Author(s):  
Fritz Klocke ◽  
Tim Herrig ◽  
Markus Zeis ◽  
Andreas Klink
Keyword(s):  
Surface Roughness ◽  
Electron Beam ◽  
Current Density ◽  
Titanium Aluminide ◽  
Titanium Aluminides ◽  
Electrochemical Machining ◽  
Dissolution Behavior ◽  
Removal Rates ◽  
Gamma Titanium Aluminide ◽  
Gamma Titanium

Additive manufacturing technologies are becoming more and more important for the implementation of efficient process chains. Due to the possibility of a near net shape, manufacturing time for finish-machining can significantly be reduced. Especially for conventionally hard to machine materials like gamma titanium aluminides (γ-TiAl), this manufacturing process is very attractive. Nevertheless, for most applications, a rework of these generative components is necessary. Independently of the mechanical material properties, electrochemical machining is one promising technology of machining these materials. Major advantages of electrochemical machining are its process-specific characteristics of high material removal rates in combination with almost no tool wear. But electrochemical machining results are highly dependent on the microstructure of the material regarding the surface roughness. Therefore, this article deals with research on electrochemical machining of electron beam melted γ-TiAl TNB-V5 compared to a casted form of this alloy. The difference between the specific removal rates as a function of current density is investigated using electrolytes based on sodium nitrate and sodium chloride. Moreover, the dissolving behavior of the electron beam melted and casted structure is analyzed by potentiostatic polarization curves. The surface roughness is heavily dependent on a homogeneous dissolution behavior of the microstructure. Thus, the mean roughness as a function of current density is investigated as well as rim zone analyses of the different structures.

EXPERIMENTAL INVESTIGATIONS INTO THE INFLUENCING PARAMETERS OF ELECTROCHEMICAL MACHINING OF AISI 202

2008 ◽  
Vol 07 (02) ◽  
pp. 337-343 ◽  
Author(s):  
T. SEKAR ◽  
R. MARAPPAN
Keyword(s):  
Surface Roughness ◽  
Metal Removal ◽  
Removal Rate ◽  
Electrochemical Machining ◽  
High Energy ◽  
Experimental Investigations ◽  
Metal Removal Rate ◽  
Hard Materials ◽  
Influencing Parameters ◽  
Traditional Process

Electrochemical machining (ECM) is a non-traditional process used mainly to cut hard or difficult to cut metals, where the application of a more traditional process is not convenient. Those difficult to cut metals demand high energy to form chips, which can result in thermal effects due to the high temperatures inherent to the process in the chip–tool interface. In traditional processes, the heat generated during the cut is dissipated to the tool, chip, workpiece and environment, affecting the surface integrity of the workpiece, mainly for those hard materials. In this work, experimental investigations have been made on the various influencing parameters involved in the Metal removal rate (MRR) and Surface roughness using ECM on AISI 202 steel. The major intervening parameters are studied and the relationship between the parameters has been determined to achieve maximum metal removal rate and minimum surface roughness by using NaNO 3-Aqua solution.

Multi-Response Optimization of Electrochemical Machining of Al-Si/B4C Composites Using RSM

2013 ◽  
Vol 3 (3) ◽  
pp. 42-56 ◽  
Author(s):  
Sadineni Rama Rao ◽  
G. Padmanabhan
Keyword(s):  
Surface Roughness ◽  
Process Parameters ◽  
Feed Rate ◽  
Electrolyte Concentration ◽  
Electrochemical Machining ◽  
Casting Process ◽  
Stir Casting ◽  
Machining Parameters ◽  
Electron Microscopic ◽  
Sem Images

The present work reports the electrochemical machining (ECM) of the aluminium-silicon alloy/boron carbide (Al-Si /B4C) composites, fabricated by stir casting process with different weight % of B4C particles. The influence of four machining parameters including applied voltage, electrode feed rate, electrolyte concentration and percentage of reinforcement on the responses surface roughness (SR) and radial over cut (ROC) were investigated. The process parameters are optimized based on the response surface methodology (RSM) and the optimum values for minimizing surface roughness and radial over cut are voltage 15.25 V, feed rate 1.0 mm/min, electrolyte concentration 13.56g/lit and percentage of reinforcement 7.36 wt%. The quality of the machined surfaces is studied by using scanning electron microscopic (SEM) images. The surface plots are generated to study the effect of process parameters and their interaction on the surface roughness and radial over cut, for the machined Al-Si/B4C composites.

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