Fabrication of porous aluminum with deep pores by using Al–In monotectic solidification and electrochemical etching

2004 ◽  
Vol 58 (6) ◽  
pp. 911-915 ◽  
Author(s):  
Hideyuki Yasuda ◽  
Itsuo Ohnaka ◽  
Shinji Fujimoto ◽  
Akira Sugiyama ◽  
Yoshinori Hayashi ◽  
...  
Keyword(s):  
Electrochemical Etching ◽  
Porous Aluminum ◽  
Monotectic Solidification

Fabrication of Porous Aluminium and Copper Media by Using Monotectic Solidification under a Magnetic Field

2006 ◽  
Vol 512 ◽  
pp. 289-294
Author(s):  
Hideyuki Yasuda ◽  
Itsuo Ohnaka ◽  
B.K. Dhindaw ◽  
Shinji Fujimoto ◽  
N. Takezawa ◽  
...  
Keyword(s):  
Magnetic Fields ◽  
Electrochemical Etching ◽  
Unidirectional Solidification ◽  
Liquid Droplets ◽  
Minor Phase ◽  
Hno3 Solution ◽  
Static Magnetic Fields ◽  
X Ray ◽  
Porous Aluminum ◽  
Monotectic Solidification

Unidirectional solidification of Al-In, Cu-Pb and Cu-Pb-Al monotectic alloys was performed under static magnetic fields up to 10T for formation of the regularly aligned-rod structure. mThe imposition of static magnetic fields exceeding 4T suppressed movement of the In liquid droplets at the Al solidifying front and enhanced the engulfment of the In droplets into the front. As a result, the eutectic-like structure was obtained in the Al-10 and 15at%In hypermonotectic alloys. The micro X-ray tomography indicated that the continuous In rods with diameters of 10-20 µm were aligned parallel to each other. In the case of the Cu-Pb and the Cu-Pb-Al alloys, the imposition of static magnetic fields also enhanced the formation of the aligned Pb rods. The electrochemical etching by using a 10% HNO3 solution successfully removed the minor phase, and the porous aluminum and copper with deep pores were fabricated.

Laser Drilling of Porous Aluminum Silicate Ceramics

2021 ◽  
Author(s):  
Ya. S. Fironov ◽  
I. V. Mel’nikov ◽  
E. R. Nadezhdin ◽  
V. N. Tokarev
Keyword(s):  
Laser Drilling ◽  
Aluminum Silicate ◽  
Porous Aluminum

scholarly journals Development and Comparative Analysis of Electrochemically Etched Tungsten Tips for Quartz Tuning Fork Sensor

Micromachines ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 286
Author(s):  
Ashfaq Ali ◽  
Naveed Ullah ◽  
Asim Ahmad Riaz ◽  
Muhammad Zeeshan Zahir ◽  
Zuhaib Ali Khan ◽  
...  
Keyword(s):  
Tuning Fork ◽  
Mechanical Stability ◽  
Electrochemical Etching ◽  
Research Work ◽  
Cone Angle ◽  
Quartz Tuning Fork ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
High Quality ◽  
Scanning Electron

Quartz Tuning Fork (QTF) based sensors are used for Scanning Probe Microscopes (SPM), in particular for near-field scanning optical microscopy. Highly sharp Tungsten (W) tips with larger cone angles and less tip diameter are critical for SPM instead of platinum and iridium (Pt/Ir) tips due to their high-quality factor, conductivity, mechanical stability, durability and production at low cost. Tungsten is chosen for its ease of electrochemical etching, yielding high-aspect ratio, sharp tips with tens of nanometer end diameters, while using simple etching circuits and basic electrolyte chemistry. Moreover, the resolution of the SPM images is observed to be associated with the cone angle of the SPM tip, therefore Atomic-Resolution Imaging is obtained with greater cone angles. Here, the goal is to chemically etch W to the smallest possible tip apex diameters. Tips with greater cone angles are produced by the custom etching procedures, which have proved superior in producing high quality tips. Though various methods are developed for the electrochemical etching of W wire, with a range of applications from scanning tunneling microscopy (SPM) to electron sources of scanning electron microscopes, but the basic chemical etching methods need to be optimized for reproducibility, controlling cone angle and tip sharpness that causes problems for the end users. In this research work, comprehensive experiments are carried out for the production of tips from 0.4 mm tungsten wire by three different electrochemical etching techniques, that is, Alternating Current (AC) etching, Meniscus etching and Direct Current (DC) etching. Consequently, sharp and high cone angle tips are obtained with required properties where the results of the W etching are analyzed, with optical microscope, and then with field emission scanning electron microscopy (FE-SEM). Similarly, effects of varying applied voltages and concentration of NaOH solution with comparison among the produced tips are investigated by measuring their cone angle and tip diameter. Moreover, oxidation and impurities, that is, removal of contamination and etching parameters are also studied in this research work. A method has been tested to minimize the oxidation on the surface and the tips were characterized with scanning electron microscope (SEM).

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