Heat dissipation properties of oxide layers formed on 7075 Al alloy via plasma electrolytic oxidation

2015 ◽  
Vol 269 ◽  
pp. 114-118 ◽  
Author(s):  
Yeon Sung Kim ◽  
Hae Woong Yang ◽  
Ki Ryong Shin ◽  
Young Gun Ko ◽  
Dong Hyuk Shin
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Heat Dissipation ◽  
Al Alloy ◽  
Oxide Layers ◽  
7075 Al Alloy ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

scholarly journals CHARACTERISTICS OF PLASMA ELECTROLYTIC OXIDATION COATINGS ON 6061 AL ALLOY PREPARED AT DIFFERENT CURRENT DENSITIES

2020 ◽  
Vol 58 (6) ◽  
pp. 699
Author(s):  
Quang-Phu Tran ◽  
Van-Da Dao ◽  
Van-Hoi Pham
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Current Mode ◽  
Coated Sample ◽  
Al Alloy ◽  
Properties Of Coatings ◽  
Sem Images ◽  
Oxide Layers ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
6061 Al Alloy

Plasma electrolytic oxidation (PEO) has earned much attention due to its powerful and easy formation of hard and corrosion-resistant oxide layers on valve metals, such as Al alloys. Here we report the effects of current density (CD) on microstructure and properties of coatings on 6061 Al alloy by PEO using direct current mode. The electrolyte contains the chemicals of Na2SiO3, Na2WO4´2H2O, and NaH2PO2´H2O. The CDs adopted 5.0, 7.5, 10.0, and 12.5 A/dm2, respectively, for a fixed PEO time of 30 min. The thickness, surface morphology, phase composition, hardness, and corrosion resistance of PEO coatings as the function of the applied CD have been studied and discussed. Studied results show the coating thickness is proportional to the applied CD. When the applied CD increases 2.5 times from 5.0 to 12.5 A/dm2, the growth rate of oxide layers increased by more than 3.5 times, from 0.423 to 1.493 μm/min, respectively. SEM images are characterized by a reduction in the ratio of agglomerate-bumps-region/flatten-region as applied CD increases. However, cracks and larger pores appear when the applied CD is higher than 10.0 A/dm2. X-ray diffraction pattern shows that the main phases of Al, g-Al2O3, α-Al2O3, and W are contained in all coatings. PEO coated sample has the highest hardness of 1290 HV and highest polarization resistance of 8.80 ´ 106 Wcm2 obtained at applied CD 10 A/dm2 which shows the best performance of the coating. The variation in coating performance is explained by microstructure details, specifically phases, compositions of oxide-layers, and micro-pores and cracks.

INCORPORATION OF MULTI-WALLED CARBON NANOTUBES INTO OXIDE LAYER FORMED ON AL ALLOY BY PLASMA ELECTROLYTIC OXIDATION

2020 ◽  
Vol 27 (11) ◽  
pp. 2050007
Author(s):  
KOANGYONG HYUN ◽  
JUNG-HYUNG LEE ◽  
SEONG-JONG KIM
Keyword(s):  
Carbon Nanotubes ◽  
Oxide Layer ◽  
Plasma Electrolytic Oxidation ◽  
Aqueous Suspension ◽  
Al Alloy ◽  
Time Curve ◽  
Oxide Layers ◽  
X Ray ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

Plasma electrolytic oxidation (PEO) is an electrochemical-based surface modification technique that produces oxide layers on valve metals. The PEO process is performed in an electrolyte solution, which offers the possibility of particles’ incorporation into the growing oxide layer. In this study, we employed a PEO technique on a commercial Al alloy in an aqueous suspension of carbon nanotubes (CNTs) to fabricate CNT-incorporated oxide layer. The voltage–time response was recorded during the process. The surface of the resulting oxide layer was characterized by means of a scanning electron microscope (SEM), an energy-dispersive X-ray spectrometer (EDS), and X-ray diffraction (XRD). It was found from the SEM observation that the CNTs were successfully incorporated into the oxide layer. The PEO with the addition of CNTs led to a delay in time to breakdown (50[Formula: see text][Formula: see text][Formula: see text]s) and a decrease in breakdown voltage (442[Formula: see text][Formula: see text][Formula: see text]V) in the voltage–time curve. The microstructural feature was clearly distinguishable between the oxide layers produced with and without CNTs: a pancake-like structure for PEO without CNTs, and a doughnut-like structure for PEO with CNTs. However, neither the results of the structure analysis nor the elemental analysis provides a clear indication of carbon, even though the presence of CNTs in the oxide layer is evident, suggesting that further optimization of CNT concentration is required.

Diamond powder incorporated oxide layers formed on 6061 Al alloy by plasma electrolytic oxidation

2018 ◽  
Vol 751 ◽  
pp. 289-298 ◽  
Author(s):  
Quang-Phu Tran ◽  
Tsung-Shune Chin ◽  
Yu-Cheng Kuo ◽  
Chong-Xun Jin ◽  
Tran Trung ◽  
...  
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Diamond Powder ◽  
Al Alloy ◽  
Oxide Layers ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic ◽  
6061 Al Alloy

Formation of uniform passive oxide layers on high Si content Al alloy by plasma electrolytic oxidation

2010 ◽  
Vol 504 ◽  
pp. S527-S530 ◽  
Author(s):  
In Jun Hwang ◽  
Duck Young Hwang ◽  
Yong Min Kim ◽  
Bongyoung Yoo ◽  
Dong Hyuk Shin
Keyword(s):  
Plasma Electrolytic Oxidation ◽  
Al Alloy ◽  
Oxide Layers ◽  
Electrolytic Oxidation ◽  
Si Content ◽  
Plasma Electrolytic

Incorporation of Carbon Nanotubes Into Oxide Layer on 7075 Al Alloy by Plasma Electrolytic Oxidation

2011 ◽  
Vol 158 (10) ◽  
pp. C325 ◽  
Author(s):  
Kang Min Lee ◽  
Jong Oh Jo ◽  
Eung Seok Lee ◽  
Bongyoung Yoo ◽  
Dong Hyuk Shin
Keyword(s):  
Carbon Nanotubes ◽  
Oxide Layer ◽  
Plasma Electrolytic Oxidation ◽  
Al Alloy ◽  
7075 Al Alloy ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic

ffect of Na2WO4 in electrolyte on mechanical properties of oxide layer on Al alloy via plasma electrolytic oxidation

2015 ◽  
Vol 53 (8) ◽  
pp. 535-540 ◽  
Author(s):  
Young Gun Ko ◽  
Dong Hyuk Shin ◽  
Hae Woong Yang ◽  
Yeon Sung Kim ◽  
Joo Hyun Park ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Oxide Layer ◽  
Plasma Electrolytic Oxidation ◽  
Al Alloy ◽  
Electrolytic Oxidation ◽  
Plasma Electrolytic
Sign in / Sign up

Export Citation Format

Share Document