scholarly journals TYPE OF WEAR OF ALUMINIUM OXIDE LAYERS DEPENDING ON MANUFACTURING PARAMETERS

Tribologia ◽  
2021 ◽  
Vol 294 (6) ◽  
pp. 39-44
Author(s):  
Mateusz Niedźwiedź
Keyword(s):  
Current Density ◽  
Current Method ◽  
Electrolyte Temperature ◽  
Eddy Current Method ◽  
Oxide Layers ◽  
Wear Process ◽  
Scratch Tests ◽  
Thickness Measurements ◽  
Manufacturing Parameters ◽  
A Current

The article presents the type of wear of Al2O3 layers produced on the aluminium alloy EN AW-5251 depending on the production parameters. Oxide layers were produced by using DC anodizing in a ternary electrolyte at variable current density and electrolyte temperature. The layer scratch tests were carried out using a Micron- Gamma microhardness tester. The scratches of oxide layers were tested for the geometric structure of the surface using a Form TalySurf 2 50i contact profilograph. Contact thickness measurements were also made using a Dualscope MP40 device based on the eddy-current method. Using a scanning microscope (SEM), photos of the sample surfaces were taken to show and compare the surface morphology of the anodized layers in various parameters. Based on the research, it can be concluded that changes in the conditions of the production process of Al2O3 layers (electrolyte temperature and current density) have an impact on the type of tribological wear and changes in layer thickness. The largest thickness of the oxide layer (19.44 μm) was measured for Sample B produced at a current density of 3A/dm2 at an electrolyte temperature of 283 K, which was also characterized by the lowest value of the ratio of parameters f1 to f2 (0.584). The smallest thickness (5.32 μm) was measured for the Sample C anodized at 1 A/dm2 at 303 K, this sample had the largest ratio f1 to f2 (1.068) for the produced Al2O3 layers. Thanks to the parameters f1 and f2 and the calculation of their ratio, the wear process for Sample B was determined as scratching and microcutting, while for Sample C as grooving.

THICKNESS MEASUREMENT OF ALUMINUM PLATES WITH A PULSED EDDY CURRENT METHOD

2008 ◽  
Vol 22 (11) ◽  
pp. 911-915 ◽  
Author(s):  
YOUNG JOO KIM ◽  
BONG YOUNG AHN ◽  
SEUNG-SEOK LEE ◽  
YOUNG-KIL SHIN
Keyword(s):  
Eddy Current ◽  
Current Method ◽  
Thickness Measurement ◽  
Eddy Current Method ◽  
Digital Oscilloscope ◽  
Pulsed Eddy Current ◽  
Metal Plates ◽  
Exciting Coil ◽  
Aluminum Plates ◽  
A Current

In this study, coil sensors that are used with a pulsed eddy current (PEC) were designed and fabricated. The proposed sensor is a differential send-receive type that eliminates the voltage induced by the direct field from the exciting coil in a PEC probe. The signal from the sensing coil is generated only on a metal specimen. For the experiment, various metal plates of different conductivities and aluminum plates of different thicknesses from 1 mm to 25 mm were prepared. A voltage square pulse was applied to an exciting coil, and the output from the sensing coil was captured by a digital oscilloscope. The applied voltage was approximately 20 volts at its greatest with a current peak of approximately 15 amperes. A 10% variation of the thickness of an aluminum plate of 20 millimeter thick was measured.

scholarly journals The amplitude-frequency measurement in non-destructive testing using the eddy current method

2018 ◽  
Vol 90 (11) ◽  
Author(s):  
Adam Kondej ◽  
Artur Szczepański
Keyword(s):  
Current Method ◽  
Frequency Measurement ◽  
Signal Frequency ◽  
Voltage Amplitude ◽  
Destructive Testing ◽  
Accurate Analysis ◽  
Eddy Current Method ◽  
Measurement Mode ◽  
Two Parameters ◽  
Thickness Measurements

The paper describes a miniaturized device that records changes in voltage amplitude and signal frequency. After applying the measuring probe to the surface of the tested material, the voltage and frequency amplitude changes. In a place free from defects and nonconformities values of voltage amplitude and frequency are taken as reference values, with which the results obtained during further tests are compared. A clear change in the value of any of the parameters indicates a change in the condition of the tested material. Registration of two parameters with different sensitivityfor selected factors allows for a more accurate analysis of the condition of the testedmaterial. The miniaturized device can works in manual measurement mode or in auto-matic mode, it can be used in defectoscopy, structure and thickness measurements.

scholarly journals The Influence of Anodic Alumina Coating Nanostructure Produced on EN AW-5251 Alloy on Type of Tribological Wear Process

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 105 ◽  
Author(s):  
Mateusz Niedźwiedź ◽  
Władysław Skoneczny ◽  
Marek Bara
Keyword(s):  
Anodic Alumina ◽  
Alumina Coating ◽  
Process Conditions ◽  
Electrolyte Temperature ◽  
Oxide Coatings ◽  
Wear Process ◽  
Scratch Tests ◽  
Method Analysis ◽  
Scanning Electron ◽  
Microhardness Tester

The article presents the influence of the anodic alumina coating nanostructure produced on aluminum alloy EN AW-5251 on the type of tribological wear process of the coating. Oxide coatings were produced electrochemically in a ternary electrolyte by the DC method. Analysis of the nanostructure of the coating was performed using ImageJ 1.50i software on micrographs taken with a scanning electron microscope (SEM). Scratch tests of the coatings were carried out using a Micron-Gamma microhardness tester. The scratch marks were subjected to surface geometric structure studies with a Form TalySurf 2 50i contact profiler. Based on the studies, it was found that changes in the manufacturing process conditions (current density, electrolyte temperature) affect changes in the coating thickness and changes in the anodic alumina coating nanostructure (quantity and diameter of nanofibers), which in turn has a significant impact on the type of tribological wear. An increase in the density of the anodizing current from 1 to 4 A/dm2 causes an increase in the diameter of the nanofibers from 75.99 ± 7.7 to 124.59 ± 6.53 nm while reducing amount of fibers from 6.6 ± 0.61 to 3.8 ± 0.48 on length 1 × 103 nm. This affects on a change in the type of tribological wear from grooving to micro-cutting.

Facet Topography and Dislocation Structure as a Possible Source for Electrical Heterogeneity in [001] TILT Bicrystals of YBa2Cu3O7-δ

1996 ◽  
Vol 54 ◽  
pp. 338-339
Author(s):  
I-Fei Tsu ◽  
D.L. Kaiser ◽  
S.E. Babcock
Keyword(s):  
Grain Boundary ◽  
Critical Current Density ◽  
Critical Current ◽  
Current Density ◽  
Electromagnetic Properties ◽  
Length Scale ◽  
Density Values ◽  
Current Densities ◽  
Applied Fields ◽  
A Current

A current theme in the study of the critical current density behavior of YBa2Cu3O7-δ (YBCO) grain boundaries is that their electromagnetic properties are heterogeneous on various length scales ranging from 10s of microns to ˜ 1 Å. Recently, combined electromagnetic and TEM studies on four flux-grown bicrystals have demonstrated a direct correlation between the length scale of the boundaries’ saw-tooth facet configurations and the apparent length scale of the electrical heterogeneity. In that work, enhanced critical current densities are observed at applied fields where the facet period is commensurate with the spacing of the Abrikosov flux vortices which must be pinned if higher critical current density values are recorded. To understand the microstructural origin of the flux pinning, the grain boundary topography and grain boundary dislocation (GBD) network structure of [001] tilt YBCO bicrystals were studied by TEM and HRTEM.

A highly stable CoMo2S4/Ni3S2 heterojunction electrocatalyst for efficient hydrogen evolution

2021 ◽  
Author(s):  
Minmin Wang ◽  
Mengke Zhang ◽  
Wenwu Song ◽  
Weiting Zhong ◽  
Xunyue Wang ◽  
...  
Keyword(s):  
Hydrogen Evolution ◽  
Current Density ◽  
A Current

A CoMo2S4/Ni3S2 heterojunction is prepared with an overpotential of only 51 mV to drive a current density of 10 mA cm−2 in 1 M KOH solution and ∼100% of the potential remains in the ∼50 h chronopotentiometric curve at 10 mA cm−2.

Real-Time Tem Studies of Electromigration in Submicron Aluminum Runners

1995 ◽  
Vol 391 ◽  
Author(s):  
S. P. Riege ◽  
A. W. Hunt ◽  
J. A. Prybyla
Keyword(s):  
Real Time ◽  
Joule Heating ◽  
Current Density ◽  
Constant Voltage ◽  
Sample Design ◽  
A Current

AbstractDirect real-time observations of electromigration (EM) in submicron Al interconnects were made using a special sample-stage which allowed TEM observations to be recorded while simultaneously heating and passing current through the sample. The samples consisted of 4000 Å thick Al(0.5wt%Cu) patterned over a TEM-transparent window into five runners in parallel, with linewidths 0.2, 0.3, 0.5, 0.8, and 1.0 μm. Both passivated and unpassivated samples were examined. A current density of 2 x 106A/cm2 was used with temperatures ranging from 200 - 350°C. The experiments were done using constant voltage testing, and we used a special sample design which dramatically minimized Joule-heating. Our approach has allowed us to directly observe voids form, grow, migrate, pin, fail a runner, and heal, all with respect to the detailed local microstructure of the runners.

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