Full-text resources of PSJD and other databases are now available in the new Library of Science.
Visit https://bibliotekanauki.pl
Preferences help
Polish version English version Language
enabled [disable] Abstract
Number of results

Results found: 9

Number of results on page
first rewind previous Page / 1 next fast forward last

Search results

help Sort By:

help Limit search:
first rewind previous Page / 1 next fast forward last
1
Content available remote

Improvement of Corrosion Properties of AL-4.08MG Alloy in Seawater by Two Step Anodizing in Electrolyte with Varied Concentration

100%
Lee S., Kim S.
Acta Physica Polonica A
|
2016
|
vol. 129
|
issue 4
742-746
EN
Aluminum is extremely active metal on the surface of which the oxide is instantly created when exposed to atmosphere. This naturally generated film has little industrial value as it has thickness as thin as 10 nm. Hence, oxide films are often made thick by electrochemical method. The characteristics of the films can be controlled by varying process parameters including composition, concentration, additives, solution temperature, voltage etc. These films have high hardness and excellent corrosion resistance. Therefore, they are receiving great amount of attention in both academic and industrial areas with their diverse applicability. In this paper, the optimal electrolyte concentration was investigated to produce oxide film with excellent corrosion resistance. The results reveal that Al₂O₃ oxide film was created on the surface for all tested electrolyte concentrations. Moreover, the films have a considerably lower corrosion current density than that of the substrate, implying excellent corrosion resistance.
2
Content available remote

Sensitizing Effects of Ti Alloying Contents on Damage Behavior of Austenitic Stainless Steel Exposed to Ultrasonic Vibratory Cavitation

100%
Lee J., Kim S.
|
EN
The cavitation damage characteristics of austenitic stainless steel with different concentrations of Ti were investigated. The microstructure of the alloys was observed with optical microscope to identify its correlation with cavitation resistance. Hardness of the alloys was measured to examine its contribution to cavitation damage. It was found that the microstructure played a more significant role in cavitation damage behavior of austenitic stainless steel with Ti than the hardness. The findings in this study revealed that Ti addition in austenitic stainless steel may present either a beneficial or detrimental effect on cavitation damage behavior, depending on the microstructural characteristics. In particular, Ti content of 1.0% represented the most deteriorated cavitation characteristics due to the formation of relatively coarse precipitates. Therefore, control of Ti concentration is essential for marine application of austenitic stainless steel.
3
Content available remote

Cavitation Damage Behavior in Seawater for Al-Mg Alloy Arc Thermal Spray Coating with Mg Content

100%
Park I., Kim S.
|
EN
Al arc thermal spray coating materials are widely used to prevent the corrosion of steel structure materials in marine environment. To improve the durability of the Al alloy thermal spray coating layer, Al-Mg alloy arc thermal spray coating was performed with different Mg contents. Furthermore, the cavitation experiment was performed in natural seawater to evaluate the durability of the thermal spray coating layer, and the damaged surface was analyzed with a scanning electron microscope and a 3D microscope. As a result, the durability of the Al-Mg alloy thermal spray coating layer improved by the addition of Mg, and the Al-3%Mg thermal spray coating layer presented the best characteristics.
4
Content available remote

Influence of Applied Frequency on Microstructural and Electrochemical Characteristics of Ceramic Coating Produced on Al-Mg Alloy by Pulsed Plasma Electrolytic Oxidation

81%
Lee J., Lee S., Kim S.
Acta Physica Polonica A
|
2016
|
vol. 129
|
issue 4
753-758
EN
Plasma electrolytic oxidation (PEO) coating is gaining attention as a promising surface treatment technique for lightweight metals and alloys such as Al, Mg and Ti. The coating involves complex interactions among various process parameters including substrate composition, current modes and electrolyte composition. In this study, ceramic coating was produced in silicate based alkaline solution on Al-Mg alloy by pulsed PEO with different applied frequencies (100, 500, 1000, 2000 Hz). The resultant coating was characterized using FE-SEM, EDS and HR-XRD. The electrochemical characteristics of the PEO coating were also investigated in seawater solution. It was found that changing frequency in the PEO process had a prominent effect on both surface and cross-sectional morphology of the coating. The electrochemical studies indicated that the pulsed PEO have improved the corrosion resistance of the Al-Mg substrate. In particular, the applied frequency of 100 Hz has produced one order of magnitude lower corrosion current density than that of the Al-Mg substrate.
5
Content available remote

Structural and Optical Properties of Hydrothermally Synthesized ZnO and Zn_{0.99}O:Eu³⁺ Powders

71%
Park K., Hakeem D., Kim J., Kim Y., Kim S.
Acta Physica Polonica A
|
2018
|
vol. 133
|
issue 4
902-906
EN
The structural and optical properties of the ZnO and Zn_{0.99}O:Eu³⁺ powders synthesized by the hydrothermal method at two different temperatures (150°C and 250°C) were studied. The ZnO and Zn_{0.99}O:0.01Eu³⁺ powders synthesized at 150 and 250°C showed rod- and flower-like morphologies, respectively. The as-synthesized and annealed ZnO and Zn_{0.99}O:0.01Eu³⁺ powders formed the wurtzite crystal structure and P6₃mc space group. The crystallite size of the as-synthesized and annealed ZnO powders increased by the incorporation of Eu³⁺. The photoluminescence properties of annealed Zn_{0.99}O:0.01Eu³⁺ powders were substantially improved by controlling the synthesis temperature. The annealed Zn_{0.99}O:0.01Eu³⁺ powders synthesized at 250°C displayed much stronger emission intensity than those at 150°C.
6
Content available remote

Time and Temperature Dependent Damage Characteristics of 5083 Al Alloy under Cavitation-Corrosion Condition

71%
Lee S., Han M., Jeong J., Kim M., Kim S.
Acta Physica Polonica A
|
2016
|
vol. 129
|
issue 4
747-752
EN
Continuous efforts to construct high-speed and lightweight ship have been made to reduce cost against growing oil prices. In this context, aluminum has received attention as an alternative material for steel, for small and medium-sized ships. In an effort to extend service life of aluminum, various researches have been attempting to improve the corrosion resistance and anti-corrosion characteristics by applying heat treatment and alloying. The material, however, has a high probability of being attacked by corrosion and erosion, caused by high ship speed in severe marine environments. Cavitation damage is dependent on several important factors, such as shape of objects, surface roughness, rotation speed, fluid pressure and velocity. Vapor pressure, density and surface tension of fluid are also taken into account. In this study, an electrochemical cavitation erosion-corrosion experiment was conducted as a function of solution temperature and applied amplitude for 5083-O aluminum alloy used commercially as a hull material for a small sized ship. The result of the experiment revealed that the damage was accelerated due to synergistic effect of corrosion and erosion as the solution temperature was elevated, and that the weight loss showed a steady increase with increasing time of cavitation.
7
Content available remote

ZnO Nanorods on Nanofibrous ZnO Seed Layers by Hydrothermal Method and Their Annealing Effects

52%
Yim K., Jeon S., Kim M., Kim S., Nam G., Lee D., Kim J., Kim J., Leem J.
Acta Physica Polonica A
|
2012
|
vol. 121
|
issue 1
214-216
EN
ZnO nanorods were grown by using the hydrothermal method on p-type Si (100) substrates with nanofibrous ZnO seed layers. Before the ZnO nanorods growth, nanofibrous ZnO seed layers were spin-coated onto the Si substrates. The structural and optical properties of ZnO nanorods were characterized by scanning electron microscopy, X-ray diffraction, and photoluminescence. The fibrous ZnO nanorods is possible due to the surface morphology of the nanofibrous ZnO seed layers. To investigate annealing effects of the ZnO nanorods, the post-annealing process was carried out at various temperatures ranging from 300 to 700C under argon conditions. The structural and optical properties of the ZnO nanorods were also affected by the post-annealing treatment.
8
Content available remote

Growth and Characterization of Indium-Doped Zinc Oxide Thin Films Prepared by Sol-Gel Method

52%
Kim M., Yim K., Kim S., Nam G., Lee D., Kim J., Kim J., Leem J.
Acta Physica Polonica A
|
2012
|
vol. 121
|
issue 1
217-220
EN
Indium-doped ZnO thin films were deposited by sol-gel spin-coating method with various In content. The effects of In content on the structural and optical properties of the indium-doped ZnO thin films were investigated by scanning electron microscopy, X-ray diffraction, and UV-visible spectroscopy. The particle-like surface morphology and the crystallinity of the indium-doped ZnO thin films were affected by change in the In content, especially at the In content of 3 at.%. The values of direct band gap were decreased with increase in the In content. The width of localized states in the optical band gap of the indium-doped ZnO thin films were changed with In content and the Urbach energy (E_{U}) was changed inversely with optical band gap of the indium-doped ZnO thin films.
9
Content available remote

Fabrication and Characterization of GaN/Polymer Composite p-n Junction with PEDOT Nanoparticle Interface Layer

42%
Kim M., Jin S., Choi H., Kim G., Yim K., Kim S., Nam G., Yoon H., Kim Y., Lee D., Kim J., Kim J., Leem J.
Acta Physica Polonica A
|
2011
|
vol. 119
|
issue 6
875-879
EN
A heavily Si-doped GaN/polymer hybrid structure with p-type poly(3,4-ethylene-dioxythiophene):beta-1,3-glucan (PEDOT nanoparticle) interface layer has been fabricated. The Si-doped GaN thin film with carrier concentration of 1 × 10^{19} cm^{-3} was grown by metal-organic chemical vapor deposition. The PEDOT nanoparticle with various sizes ranging from 60 to 120 nm was synthesized via a miniemulsion polymerization process. The electrical conductivity of the PEDOT nanoparticle is less than 1.2 S/cm. The current-voltage (I-V) characteristic of the hybrid structure shows diode-like behavior. The I-V characteristic was examined in the framework of the thermionic emission model. The ideality factor of the structure without PEDOT nanoparticle interface layer is 12.9. However, the ideality factor of the hybrid structure with PEDOT nanoparticle interface layer is obtained as 1.9. The value of ideality factor is dramatically decreased by inserting the PEDOT nanoparticle interface layer.
first rewind previous Page / 1 next fast forward last
JavaScript is turned off in your web browser. Turn it on to take full advantage of this site, then refresh the page.