Effects of Pretreatment on the Etch Pit Formation during the Electrochemical Etching of Aluminum

2007 ◽  
Vol 124-126 ◽  
pp. 1561-1564
Author(s):  
Jae Kwang Lee ◽  
Yun Ho Shin ◽  
Jin Wook Kang ◽  
Yong Sug Tak
Keyword(s):  
Electrochemical Etching ◽  
High Density ◽  
Aluminum Surface ◽  
Etch Pits ◽  
Phosphate Ion ◽  
Etch Pit ◽  
Pit Formation ◽  
Fluorosilicic Acid ◽  
Etching Behavior ◽  
Chemical Pretreatments

The effect of chemical pretreatments on the electrochemical etching behavior of aluminum was investigated with the topographic studies of surface and the analysis of initial potential transients. Two-step pretreatments with H3PO4 and H2SiF6 result in a high density of pre-etch pits on aluminum surface by the incorporation of phosphate ion inside the oxide film and the removal of surface layer by aggressive fluorosilicic acid solution. It generates a high density of etch pits during electrochemical etching and results in the capacitance increase of etched Al electrode by expanding the surface area, up to 61.3 μF/cm2 with the pretreatment solution of 0.5M H3PO4 at 65°C and 10 mM H2SiF6 at 45°C.

Dislocations in SiC Revealed by NaOH Vapor Etching and a Comparison with X-Ray Topography Taken with Various g-Vectors

2016 ◽  
Vol 858 ◽  
pp. 389-392 ◽  
Author(s):  
Yong Zhao Yao ◽  
Yukari Ishikawa ◽  
Yoshihiro Sugawara ◽  
Koji Sato ◽  
Katsunori Danno ◽  
...  
Keyword(s):  
Threading Dislocations ◽  
Etch Pits ◽  
Burgers Vector ◽  
Monochromatic Beam ◽  
X Ray ◽  
Etch Pit ◽  
Pit Formation ◽  
Dislocation Behavior ◽  
Koh Etching

Threading dislocations (TDs) in 4H-SiC have been studied by comparing etch pits formed by NaOH vapor etching with results of synchrotron monochromatic-beam X-ray topography (XRT) taken under different g-vectors. Burgers vectors determined based on XRT results were utilized to investigate the etch pit characteristics of edge (TED), screw (TSD) and mixed (Burgers vector b=c+a, TMD) threading dislocations. It has been found that pit formation by NaOH vapor etching was very different to that by conventional molten KOH etching. We discuss the possibility of using NaOH vapor etching to distinguish TMDs from TSDs, and report a variety of characteristic etch pits formed by this method and their correlations to dislocation behavior.

Influence of Ultrasound Power on the Formation of Submicron Etch Pits during Sonoelectrochemical Etching of Aluminum

2006 ◽  
Vol 326-328 ◽  
pp. 433-436 ◽  
Author(s):  
Jin Wook Kang ◽  
Eun Seong Ko ◽  
Jae Kwang Lee ◽  
Yong Sug Tak
Keyword(s):  
Electrochemical Etching ◽  
Film Formation ◽  
Length Distribution ◽  
Anodic Oxide ◽  
Bulk Solution ◽  
Ultrasonic Power ◽  
Etch Pit Density ◽  
Tunnel Length ◽  
Etch Pits ◽  
Etch Pit

Ultrasound was superimposed during electrochemical etching of aluminum and the effect of ultrasonic power on the formation and growth of etch pits were analyzed with the measurement of fast potential transient and morphology study. Ultrasound contributed the increase of etch pit density by prohibiting anodic oxide film formation and induced uniform tunnel length distribution. Current step reduction experiments indicated the enhanced mass transfer both inside tunnel and bulk solution with the increase of ultrasonic power. The capacitance of etched foil was increased by 40% with 600W of 28 KHz ultrasonic power.

Experimental investigation of etch pit formation on quartz sand grains

1979 ◽  
Vol 116 (6) ◽  
pp. 477-482 ◽  
Author(s):  
P. Wilson
Keyword(s):  
Experimental Investigation ◽  
Quartz Sand ◽  
Natural Occurrence ◽  
Etch Pits ◽  
Etch Pit ◽  
Pit Formation ◽  
Time Periods ◽  
Materials Used ◽  
Quartz Grains

SummaryAn experimental investigation into the formation of crystallographically orientated etch pits on quartz sand grains was undertaken. The methods and materials used in the experiments differ considerably from those of other workers in this field. Using natural as opposed to artificial solutions, V-shaped or triangular etch pits as well as rectangular pits have been produced on the quartz grains after time periods of 4 hours and 20 hours. Features of intense surface disintegration have also been recorded. The etch pits are compared to those of natural occurrence on grains from the Millstone Grit (Namurian) sediments and the differences discussed.

Scanning Tunneling Microscope Study of Etch Pits on Highly Oriented Pyrolytic Graphite Heated in an Atomic Absorption Electrothermal Analyzer

1997 ◽  
Vol 51 (12) ◽  
pp. 1896-1904 ◽  
Author(s):  
Kurt G. Vandervoort ◽  
Kristin N. McLain ◽  
David J. Butcher
Keyword(s):  
Elevated Temperatures ◽  
Pyrolytic Graphite ◽  
Reaction Rates ◽  
Surface Reactivity ◽  
Scanning Tunneling ◽  
Highly Oriented Pyrolytic Graphite ◽  
Tunneling Microscopy ◽  
Etch Pits ◽  
Pit Formation ◽  
Second Period

Scanning tunneling microscopy (STM) was used to elucidate monolayer etch pits that form on highly oriented pyrolytic graphite (HOPG) heated in an electrothermal analyzer. Pits form at elevated temperatures due to reactions between oxygen and exposed carbon edge atoms (defects) and additionally with intraplanar carbon atoms (through abstraction). Samples of HOPG without analyte or matrix modifier were placed in the depression of a pure pyrolytic graphite platform and heated by using standard analysis furnace programs. Under argon stop-flow conditions, pits form in less than a second at atomization temperatures equal to and above 1200 °C. With low argon flow rates (40 mL/min), pits formed at atomization temperatures equal to and greater than 1750 °C in less than a second. Quantitative pit formation rates were used to indicate oxygen partial pressure, which may be as high as ∼ 10−3 atm at 1200 °C. Reaction rates were used to predict surface degradation due to oxygen attack and determine that 1-μm depth normal to the surface would be removed by 200 successive 5-second-period furnace firings at 1200 °C. Implications for increases in surface reactivity and analyte intercalation are discussed.

scholarly journals ECE laboratory in the Vinca institute: Its basic characteristics and fundamentals of electrochemic etching on polycarbonate

2003 ◽  
Vol 18 (2) ◽  
pp. 57-60 ◽  
Author(s):  
Zora Zunic ◽  
Predrag Ujic ◽  
Igor Celikovic ◽  
Kenzo Fujimoto
Keyword(s):  
Large Scale ◽  
Electrochemical Etching ◽  
Initial Step ◽  
Field Application ◽  
Alpha Particles ◽  
Experimental Phase ◽  
Laboratory Equipment ◽  
Etch Pit ◽  
Large Scale Survey ◽  
Basic Characteristics

This paper deals with the introductory aspects of the Electrochemical Etching Laboratory installed at the VINCA Institute in the year 2003. The main purpose of the laboratory is its field application for radon and thoron large-scale survey using passive radon/thoron UFO type detectors. Since the etching techniques together with the laboratory equipment were transferred from the National Institute of Radiological Sciences, Chiba, Japan, it was necessary for both etching conditions to be confirmed and to be checked up^ i. e., bulk etching speeds of chemical etching and electrochemical etching in the VINCA Electrochemical Etching Laboratory itself. Beside this initial step, other concerns were taken into consideration in this preliminary experimental phase such as the following: the measurable energy range of the polycarbonate film, background etch pit density of the film and its standard deviation and reproducibility of the response to alpha particles for different sets of etchings.

scholarly journals Nanoscale morphological evolution of monocrystalline Pt surfaces during cathodic corrosion

2020 ◽  
Vol 117 (51) ◽  
pp. 32267-32277 ◽  
Author(s):  
Nakkiran Arulmozhi ◽  
Thomas J. P. Hersbach ◽  
Marc T. M. Koper
Keyword(s):  
Growth Stage ◽  
Morphological Evolution ◽  
Local Symmetry ◽  
Alkaline Electrolyte ◽  
Etch Pits ◽  
Etch Pit ◽  
Diffusion Limited ◽  
Second Growth ◽  
Ternary Metal ◽  
Electrochemical Phenomenon

This paper studies the cathodic corrosion of a spherical single crystal of platinum in an aqueous alkaline electrolyte, to map out the detailed facet dependence of the corrosion structures forming during this still largely unexplored electrochemical phenomenon. We find that anisotropic corrosion of the platinum electrode takes place in different stages. Initially, corrosion etch pits are formed, which reflect the local symmetry of the surface: square pits on (100) facets, triangular pits on (111) facets, and rectangular pits on (110) facets. We hypothesize that these etch pits are formed through a ternary metal hydride corrosion intermediate. In contrast to anodic corrosion, the (111) facet corrodes the fastest, and the (110) facet corrodes the slowest. For cathodic corrosion on the (100) facet and on higher-index surfaces close to the (100) plane, the etch pit destabilizes in a second growth stage, by etching faster in the (111) direction, leading to arms in the etch pit, yielding a concave octagon-shaped pit. In a third growth stage, these arms develop side arms, leading to a structure that strongly resembles a self-similar diffusion-limited growth pattern, with strongly preferred growth directions.

scholarly journals A Technique for Producing Strain-Free Flat Surfaces on Single Crystals of Ice

1970 ◽  
Vol 9 (57) ◽  
pp. 385-390 ◽  
Author(s):  
T. M Tobin ◽  
K. Itagaki
Keyword(s):  
Dislocation Density ◽  
Single Crystals ◽  
Aluminum Surface ◽  
Ice Crystal ◽  
X Ray ◽  
Flat Surfaces ◽  
Etch Pit

The top surface of an accurately aligned ice crystal is melted by an aluminum surface and then frozen to a warm “Lucite” plate ant! tapped free. Etch-pit development shows that the dislocation density on the resulting surface is similar to die bulk dislocation density determined by X-ray topographic methods.

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