scholarly journals Wire Electrochemical Micromachining of Aluminum Rings for the Fabrication of Short-Millimeter Corrugated Horns

Micromachines ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 122 ◽  
Author(s):  
Xiaolong Fang ◽  
Xiangyang Wang ◽  
Jiacheng Zhu ◽  
Yongbin Zeng ◽  
Ningsong Qu
Keyword(s):  
Optimal Parameter ◽  
Nitrate Solution ◽  
Groove Depth ◽  
Electrochemical Micromachining ◽  
Experimental Investigations ◽  
Complexing Agent ◽  
Obvious Effect ◽  
Wire Electrochemical Micromachining ◽  
Sodium Nitrate Solution ◽  
Helical Electrode

With the increase of working frequency, the feature size of a corrugated horn will be greatly reduced, causing challenges for fabrication. This paper investigated wire electrochemical micromachining (WECMM) of aluminum rings for assembly of a mandrel for electroforming, which has been a primary method for producing corrugated horns. By utilizing a rotary helical electrode and green additives, the removal efficiency of electrolytic products in WECMM was improved. It was found that the machined slits had good unilateral consistency on the left side of the electrode feeding direction when the electrode rotated clockwise. Complexing agent glutamic diacetic acid (GLDA) can compete with OH− for Al3+ and has an obvious effect in reducing insoluble electrolytic products. From experimental investigations on typical parameters, an optimal parameter combination considering slit homogeneity and machining efficiency was obtained. In an electrolyte solution containing 15 g/L sodium nitrate solution and 15 g/L GLDA, 100 μm-thick aluminum rings with good edge and surface qualities were fabricated at a rate of 1.2 μm/s using a helical electrode with a diameter of 0.3 mm. Finally, these aluminum rings were successfully applied to make an internal corrugated sample with a rib width of 100 μm and a groove depth of 500 μm.

Modeling and Numerical Analysis of Advanced Machining for Orthotic Components

2019 ◽  
pp. 230-271
Author(s):  
Pankaj Charan Jena ◽  
Barsarani Pradhan ◽  
D. Dhupal
Keyword(s):  
Geometric Model ◽  
Nitrate Solution ◽  
Flow Analysis ◽  
Flow Simulation ◽  
Turbulent Energy ◽  
Vital Role ◽  
Electrochemical Micromachining ◽  
Electrode Gap ◽  
Advanced Machining ◽  
Sodium Nitrate Solution

Electrochemical micromachining plays a vital role in the advanced machining domain. Particularly, it helps the medical industry in machining micro-level devices in hardened materials. Though it is maintaining a very small inter-electrode gap during machining, it is required to understand suitable machining parameters before machining. These parameters can be achieved by proper modeling and simulation. In this chapter, a model for flow analysis of electrolytes in inter-electrode gaps is designed to obtain optimal process parameters for machining. The geometric model used in this simulation consists of cylindrical workpiece, an inlet allowing the flow of sodium nitrate solution as electrolyte to the machining zone, and a cylindrical tool with a flat end. Electrolytic flow simulation is incorporated using computational fluid dynamics by ANSYS–CFX 15.0 for finding pressure variation, streamline velocity pattern, turbulent energy, and temperature contour in IEG. According to the CFD analysis, the passivation effect, stagnation effect, pressure, and temperature zone are studied.

scholarly journals Antimicrobial Bacterial Cellulose-Silver Nanoparticles Composite Membranes

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Hernane S. Barud ◽  
Thaís Regiani ◽  
Rodrigo F. C. Marques ◽  
Wilton R. Lustri ◽  
Younes Messaddeq ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Silver Nanoparticles ◽  
Bacterial Cellulose ◽  
Nitrate Solution ◽  
Composite Membranes ◽  
Silver Nitrate Solution ◽  
Complexing Agent ◽  
X Ray Diffraction ◽  
Gram Positive Bacteria ◽  
Transmission Electron

Antimicrobial bacterial cellulose-silver nanoparticles composite membranes have been obtained by“in situ”preparation of Ag nanoparticles from hydrolytic decomposition of silver nitrate solution using triethanolamine as reducing and complexing agent. The formation of silver nanoparticles was evidenced by the X-ray diffraction, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and absorption in the UV-Visible (350 nm to 600 nm). Thermal and mechanical properties together with swelling behavior for water were considered. TEA concentration was observed to be important in order to obtain only Ag particles and not a mixture of silver oxides. It was also observed to control particle size and amount of silver contents in bacterial cellulose. The composite membranes exhibited strong antimicrobial activity against Gram-negative and Gram-positive bacteria.

scholarly journals Insights on the Influence of Surface Chemistry and Rim Zone Microstructure of 42CrMo4 on the Efficiency of ECM

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2132
Author(s):  
Alexander Schupp ◽  
Oliver Beyss ◽  
Bob Rommes ◽  
Andreas Klink ◽  
Daniela Zander
Keyword(s):  
Mixed Oxide ◽  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Material Removal ◽  
Chemical Elements ◽  
Nitrate Solution ◽  
Electrochemical Machining ◽  
Process Efficiency ◽  
Negative Effect ◽  
Sodium Nitrate Solution

The electrochemical machining (ECM) of 42CrMo4 steel in sodium nitrate solution is mechanistically characterized by transpassive material dissolution and the formation of a Fe3−xO4 mixed oxide at the surface. It is assumed that the efficiency of material removal during ECM depends on the structure and composition of this oxide layer as well as on the microstructure of the material. Therefore, 42CrMo4 in different microstructures (ferritic–pearlitic and martensitic) was subjected to two ECM processes with current densities of about 20 A/cm2 and 34 A/cm2, respectively. The composition of the process electrolyte was analyzed via mass spectrometry with inductively coupled plasma in order to obtain information on the efficiency of material removal and the reaction mechanisms. This was followed by an X-ray photoelectron spectroscopy analysis to detect the chemical composition and the binding states of chemical elements in the oxide formed during ECM. In summary, it has been demonstrated that the efficiency of material removal in both ECM processes is about 5–10% higher for martensitic 42CrMo4 than for ferritic–pearlitic 42CrMo4. This is on one hand attributed to the presence of the cementite phase at ferritic–pearlitic 42CrMo4, which promotes oxygen evolution and therefore has a negative effect on the material removal efficiency. On the other hand, it is assumed that an increasing proportion of Fe2O3 in the mixed oxide leads to an increase in the process efficiency.

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