scholarly journals Oxide Film Formation on a Microcrystalline Al Alloy at Various Temperatures in Neutral Borate Solution

1997 ◽  
Vol 144 (10) ◽  
pp. 3377-3384
Author(s):  
S. C. Thomas ◽  
V. I. Birss
Keyword(s):  
Oxide Film ◽  
Film Formation ◽  
Al Alloy ◽  
Borate Solution

scholarly journals Oxide Film Formation on a Microcrystalline Al Alloy in Sulfuric Acid

1997 ◽  
Vol 144 (4) ◽  
pp. 1353-1361 ◽  
Author(s):  
S. C. Thomas ◽  
V. I. Birss
Keyword(s):  
Sulfuric Acid ◽  
Oxide Film ◽  
Film Formation ◽  
Al Alloy

Synthesis and Characterisation of Anodized Powder Metallurgy Mg-Ca Alloy

2018 ◽  
Vol 280 ◽  
pp. 221-225
Author(s):  
C.D. Zuraidawani ◽  
F.W. Norhadira ◽  
Mochd Nazree B. Derman
Keyword(s):  
Powder Metallurgy ◽  
Oxide Film ◽  
Vickers Hardness ◽  
Film Formation ◽  
Surface Hardness ◽  
Powder Metallurgy Method ◽  
Xrd Pattern ◽  
Surface Changes

The Mg-1wt.%Ca alloy was fabricated using powder metallurgy method. The anodizing process were done by using different voltage (5V, 15V, 25V) and concentration of KOH (0.1M, 0.5M, 1.0M). The surface changes on PM Mg/1wt.%Ca resulted by anodizing was analyzed using SEM-EDX and XRD pattern. Meanwhile, surface hardness was measured by micro-Vickers hardness machine. The experiment found different XRD pattern between all non-anodized and anodized samples. The study found that increasing the voltage will increase the hardness while increasing KOH concentration reduced the hardness. The relation of the hardness and oxide film formation can be analyzed using SEM-EDX and XRD pattern. The optimum value for voltage, KOH concentration and hardness are 25V, 0.1M and 27.2 HV. The XRD detect the changes in PM Mg/1wt.% Ca indicates the oxide film formation.

Oxide scale behavior of Al–7.5 mass%Mg alloy containing trace Ca during short-term oxidation

2021 ◽  
Vol 11 (11) ◽  
pp. 1881-1886
Author(s):  
Seong-Ho Ha ◽  
Young-Ok Yoon ◽  
Bong-Hwan Kim ◽  
Hyun-Kyu Lim ◽  
Sung-Hwan Lim ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Oxide Film ◽  
Phase Diagrams ◽  
Film Formation ◽  
Mg Alloy ◽  
Short Term ◽  
Spinel Formation ◽  
Transmission Electron ◽  
Significant Difference

In this study, using transmission electron microscopy and phase diagrams from thermodynamic calculations, we investigated the oxide film formation of Al–7.5 mass%Mg alloy containing Ca traces during short-term oxidation in terms of the thermodynamic stability and multi-element oxides by inter-diffusion based on the results of analysis for the oxide film. For the oxidation test at 515 ˚C, for 1 h, its results showed that there is no significant difference between the Ca-added and Ca-free Al–7.5 mass%Mg alloys was observed, while further exposure caused the Ca-free alloy to gain significant weight. Based on the standard Gibbs free energy for oxide production calculated in this study, CaO was the most preferential product among the single metal oxides examined. As per calculations for MgAl2O4-spinel formation reactions, the spinel formation from MgO was thermodynamically the most favorable. According to the phase diagrams calculated in this study, various multi-element oxides including Ca could possibly form in the oxide layer of Ca-added alloy. The analysis results of transmission electron microscopy confirmed that MgO is the primary oxide in the Al–Mg binary alloys. In oxidation tests conducted for less than 1 h, the spinel was rarely found. The outmost areas of oxide layers correspond to MgO and CaO in Ca-free and Ca-added alloys, respectively. However, in the Ca-added alloy, the inner layer contains certain amounts of Ca, Al, and Mg.

Thermal regimes of passivative oxide film formation on Al surface: Theoretical and experimental study

2006 ◽  
Vol 600 (20) ◽  
pp. 4796-4800 ◽  
Author(s):  
Anatoly B. Belonoshko ◽  
Anders Rosengren ◽  
Gunnar Hultquist
Keyword(s):  
Experimental Study ◽  
Oxide Film ◽  
Film Formation ◽  
Thermal Regimes

Effect of Voltage on Mg-Li-Al Alloy Anodic Oxide Film

2018 ◽  
Vol 941 ◽  
pp. 1194-1197 ◽  
Author(s):  
Naoya Miyakita ◽  
Natsuki Tanigaki ◽  
Taiki Morishige ◽  
Toshihide Takenaka
Keyword(s):  
Oxide Film ◽  
Phosphoric Acid ◽  
Anodic Oxidation ◽  
Surface Coating ◽  
Low Voltage ◽  
Active Surface ◽  
Anodic Oxide ◽  
Al Alloys ◽  
Anodic Oxide Film ◽  
Al Alloy

Anodic oxidation of Mg-Li-Al alloys using phosphoric acid-based bath were processed to obtain the corrosion-proof surface coating. The specimen oxidized at low voltage anodically dissolved without the formation of oxidized film. Anodic oxidation film could be formed at higher voltage due to thin layer preferentially formed on tthe active surface, this layer develops to stable thick film. There were no significant differences in film thickness between LA141 and LA143 alloys.

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