Effects of balance electrode in deep micro-holes drilling in “nickel plate” through µECM process using H2SO4 electrolyte

Author(s):  
Md. Zishanur Rahman ◽  
Alok Kumar Das ◽  
Somnath Chattopadhyaya
Keyword(s):  
Author(s):  
Akira Tanaka ◽  
David F. Harling

In the previous paper, the author reported on a technique for preparing vapor-deposited single crystal films as high resolution standards for electron microscopy. The present paper is intended to describe the preparation of several high resolution standards for dark field microscopy and also to mention some results obtained from these studies. Three preparations were used initially: 1.) Graphitized carbon black, 2.) Epitaxially grown particles of different metals prepared by vapor deposition, and 3.) Particles grown epitaxially on the edge of micro-holes formed in a gold single crystal film.The authors successfully obtained dark field micrographs demonstrating the 3.4Å lattice spacing of graphitized carbon black and the Au single crystal (111) lattice of 2.35Å. The latter spacing is especially suitable for dark field imaging because of its preparation, as in 3.), above. After the deposited film of Au (001) orientation is prepared at 400°C the substrate temperature is raised, resulting in the formation of many square micro-holes caused by partial evaporation of the Au film.


Author(s):  
Shailesh R. Sheth ◽  
Jayesh R. Bellare

Specimen support and astigmatism correction in Electron Microscopy are at least two areas in which lacey polymer films find extensive applications. Although their preparation has been studied for a very long time, present techniques still suffer from incomplete release of the film from its substrate and presence of a large number of pseudo holes in the film. Our method ensures complete removal of the entire lacey film from the substrate and fewer pseudo holes by pre-treating the substrate with Gum Arabic, which acts as a film release agent.The method is based on the classical condensation technique for preparing lacey films which is essentially deposition of minute water or ice droplets on the substrate and laying the polymer film over it, so that micro holes are formed corresponding to the droplets. A microscope glass slide (the substrate) is immersed in 2.0% (w/v) aq. CTAB (cetyl trimethyl ammonium bromide)-0.22% (w/v) aq.


2018 ◽  
Vol 9 (2) ◽  
pp. 121-126
Author(s):  
Yanfei Zhang ◽  
Jinliang Gong ◽  
Bin Liu ◽  
Xiangkuan Cao ◽  
Zhiwen Wang

Author(s):  
Salman Khani ◽  
Seyedhamidreza Shahabi Haghighi ◽  
Mohammad Reza Razfar ◽  
Masoud Farahnakian

In this paper, the thread turning of aluminum 7075-T6 alloy is studied using micro-hole textured solid-lubricant embedded carbide inserts. The primary focus of this work is to enhance the performance of the thread turning process for producing high quality threaded parts. To achieve this, micro-holes were generated by laser micro-machining on the rake face of tools and then, MoS2 and CNT (carbon nanotube) solid-lubricants were embedded into micro-holes. The effects of micro-holes and solid-lubrication on the performance of the thread turning process were examined using traditional tool ( T0), micro-hole textured tool ( T1), micro-hole textured MoS2 embedded tool ( T2), and micro-hole textured CNT embedded tool ( T3). In this study, cutting forces, chip-tool contact length, built-up edge (BUE), surface roughness, and operating cost were investigated. The influence of micro-hole generation on the mechanical strength of cutting inserts was evaluated using the finite element method. The results showed that the fabrication of the micro-holes on the rake surface of cutting inserts has no significant effect on the mechanical strength of the tools. The comparisons of our method with traditional tools demonstrated that the cutting performance improved in the threading process. Our results reveal that the main cutting force, radial thrust force, surface roughness, built-up edge, and chip-tool contact length reduced 37.1%, 40.9%, 37.9%, 58.3%, and 38.2%, respectively, as T3 tools are applied in this process. A cost analysis, based on estimated tooling costs, showed that the T3 tool can yield an 18% reduction in overall operating cost.


2021 ◽  
Vol 1865 (2) ◽  
pp. 022004
Author(s):  
Chunyan Yang ◽  
Yun Hao ◽  
Yangping Li ◽  
Bozhe Wang ◽  
Hai Yuan ◽  
...  

2016 ◽  
Vol 25 ◽  
pp. 1234-1241 ◽  
Author(s):  
Abhishek Kumar ◽  
Somashekhar S. Hiremath
Keyword(s):  

2010 ◽  
Vol 126-128 ◽  
pp. 885-890
Author(s):  
K.P. Somashekhar ◽  
N. Ramachandran ◽  
Jose Mathew

This work is on the preparation of microelectrodes for μ-EDM operation using μ-WEDG process. Electrodes of Ø500 μm are fabricated with various discharge energy machining conditions. Effects of gap voltage, capacitance & feed rate on the surface finish of the electrodes and overcut of the thus produced micro holes are investigated. The profile of microelectrodes is measured using surface roughness tester with 2μm stylus interfaced with SURFPAK software. The study demonstrated that for brass electrodes an arithmetic average roughness value as low as 1.7μm and an overcut of 3 µm could be achieved. The significant machining parameters are found using ANOVA. Surface of the produced microelectrodes are examined using Scanning Electron Microscope. μ-WEDG process parameters could be adjusted to achieve good surface integrity on microelectrodes. Experimental results showed that the surface roughness of microelectrodes depended primarily on feed rate of the electrode. The observations showed the clear and quantitative correlation existing between the micrometer level surface quality and process parameters. The resulting microelectrodes are found to be of exceptionally high quality and could be used for μ- EDM operation on different types of work materials.


1967 ◽  
Vol 89 (1) ◽  
pp. 29-38 ◽  
Author(s):  
P. F. Pucci ◽  
C. P. Howard ◽  
C. H. Piersall

The single-blow, transient testing technique for determining the heat transfer characteristics of heat exchanger surfaces, with a summary of the underlying theory, a description of an experimental facility, and comments on the applicability of the technique, are presented. Heat transfer and flow friction data are presented for plate-fin type surfaces fabricated of perforated nickel plate. The data indicate that perforations increase heat transfer performance without a large frictional power penalty.


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