Corrosion Resistance of the Ceramic Coating Formed by Micro-Plasma Arc Oxidation on AZ91D Alloy

2007 ◽  
pp. 2451-2453
Author(s):  
Shu Hua Li ◽  
Fu Chi Wang
Keyword(s):  
Corrosion Resistance ◽  
Ceramic Coating ◽  
Az91d Alloy ◽  
Plasma Arc

Corrosion Resistance of the Ceramic Coating Formed by Micro-Plasma Arc Oxidation on AZ91D Alloy

2007 ◽  
Vol 336-338 ◽  
pp. 2451-2453
Author(s):  
Shu Hua Li ◽  
Fu Chi Wang
Keyword(s):  
Magnesium Alloy ◽  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Az91d Alloy ◽  
Plasma Arc ◽  
X Ray Diffraction ◽  
Compact Layer ◽  
Az91d Magnesium Alloy ◽  
Loose Layer ◽  
Salt Fog

The ceramic coating was formed by micro-plasma arc oxidation (MPAO) on AZ91D magnesium alloy. The surface and section morphology of coatings were observed using scanning electron microscopy. The phase composition of coatings was analyzed by X-ray diffraction. The method of salt fog experimental was carried out to proof-test performances of anti-corrosion of material. The results showed that the ceramic coating was composed by loose layer and compact layer. The coating surface has a large number of grains with various sizes. In addition, there is also a lot of pore in the loose layer, but the compact layer is tighter than the loose layer. Compact layer has a good combination with substrate magnesium alloy. The MPAO coating is mainly composed of silica oxide (MgAl2Si3O12 and β-Mg2SiO4 and (Mg4Al14) (Al4Si2)O20) and composite oxide of Mg and Al (δ-MgAl28O4). The performance of resistant corrosion of AZ91D coved by ceramic coating is higher than AZ91D magnesium alloy. The corrosion ratio of AZ91D alloy coved by ceramic coatings to AZ91D alloy is 1:8.61.

scholarly journals Applying Baghdadite/PCL/Chitosan Nanocomposite Coating on AZ91 Magnesium Alloy to Improve Corrosion Behavior, Bioactivity, and Biodegradability

Coatings ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 789 ◽  
Author(s):  
Farzad Soleymani ◽  
Rahmatollah Emadi ◽  
Sorour Sadeghzade ◽  
Fariborz Tavangarian
Keyword(s):  
Corrosion Resistance ◽  
Biomedical Applications ◽  
Corrosion Current Density ◽  
Ceramic Coating ◽  
Alloy Coating ◽  
Corrosion Current ◽  
Nanocomposite Coating ◽  
Az91 Alloy ◽  
Az91 Magnesium Alloy ◽  
Az91 Magnesium

Magnesium alloys have received a great amount of attention regarding being used in biomedical applications; however, they show high degradability, poor bioactivity, and biocompatibility. To improve these properties, surface modification and various types of coatings have been applied. In this study, an anodized AZ91 alloy was coated with a polymer matrix composite made of polycaprolactone/chitosan (PCL/Ch) with different percentages of baghdadite to improve its resistance to corrosion, bioactivity, and biocompatibility. The effects of different percentages of baghdadite (0 wt %, 1 wt %, 3 wt %, and 5 wt %) on the surface microstructure, corrosion resistance, roughness, and wettability were evaluated. The results indicated that the applied nano-polymer-ceramic coating including 3 wt % baghdadite was hydrophobic, which consequently increased the corrosion resistance and decreased the corrosion current density of the anodized AZ91 alloy. Coating with 3 wt % baghdadite increased the roughness of AZ91 from 0.329 ± 0.02 to 7.026 ± 0.31 μm. After applying the polymer-ceramic coating on the surface of anodized AZ91, the corrosion products changed into calcium–phosphate compounds instead of Mg(OH)2, which is more stable in a physiological environment.

scholarly journals Fabrication and Characterization of Ceramic Coating on Al7075 Alloy by Plasma Electrolytic Oxidation in Molten Salt

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 993
Author(s):  
Alexander Sobolev ◽  
Tamar Peretz ◽  
Konstantin Borodianskiy
Keyword(s):  
Corrosion Resistance ◽  
Molten Salt ◽  
Plasma Electrolytic Oxidation ◽  
Ceramic Coating ◽  
Electrochemical Impedance ◽  
Current Frequency ◽  
Electrolytic Oxidation ◽  
Fabrication And Characterization ◽  
Plasma Electrolytic

The fabrication of a ceramic coating on the metallic substrate is usually applied to achieve the improved performance of the material. Plasma electrolytic oxidation (PEO) is one of the most promising methods to reach this performance, mostly wear and corrosion resistance. Traditional PEO is carried out in an aqueous electrolyte. However, the current work showed the fabrication and characterization of a ceramic coating using PEO in molten salt which was used to avoid disadvantages in system heating-up and the formation of undesired elements in the coating. Aluminum 7075 alloy was subjected to the surface treatment using PEO in molten nitrate salt. Various current frequencies were applied in the process. Coating investigations revealed its surface porous structure and the presence of two oxide layers, α-Al2O3 and γ-Al2O3. Microhardness measurements and chemical and phase examinations confirmed these results. Potentiodynamic polarization tests and electrochemical impedance spectroscopy revealed the greater corrosion resistance for the coated alloy. Moreover, the corrosion resistance was increased with the current frequency of the PEO process.

Effect of Mechanical Properties and Corrosion Behaviour of Martensitic Stainless Steel 410 1.6mm Butt Welded by Plasma Arc Welding

2019 ◽  
Vol 969 ◽  
pp. 601-606
Author(s):  
M. Sree Arravind ◽  
S. Ramesh Kumar ◽  
S. Senthil Kumaran ◽  
D. Venkateswarlu
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Tensile Test ◽  
Arc Welding ◽  
Martensitic Stainless Steel ◽  
Laser Beam Welding ◽  
Plasma Arc Welding ◽  
Plasma Arc ◽  
Butt Weld ◽  
Welding Processes

Plasma Arc Welding (PAW) is one of the important arc welding processes used in electronics, medical, automotive and aerospace industries due its high accuracy and ability of welding any hard materials which is more tolerant to joint misalignment than Laser Beam Welding (LBW) at a lower cost. Thickness of 1.6mm plates were used to obtain full penetration and a strong joint with a very narrow Heat Affected Zone. The present study deals with the effect of mechanical and corrosion resistance properties of butt welded 1.6 mm thick martensitic stainless steel-similar (SS410 and SS410) joints made by plasma arc welding technique. Similar butt Welded joints were analyzed by using mechanical (Bend test, Erichsen cup test, Tensile test) characterization methods. Their corresponding corrosion resistance properties were also investigated by potentiodynamic polarization corrosion testing technique. The tensile strength was found to be 341 MPa for similar SS410 weld. During tensile test the failure occurred on the base metal on both similar joints Keywords: SS304; SS410; PAW; Butt weld; Erichsen Cup Test; Microstructure.

The Effects of Magnetic Field on Micro-Arc Oxidation Ceramic Coating on Magnesium Alloys

2014 ◽  
Vol 960-961 ◽  
pp. 143-147
Author(s):  
Jun Zhao ◽  
Jian Jun Xi ◽  
Zhi Gang Wang ◽  
Chun Ping Zhao
Keyword(s):  
Magnetic Field ◽  
Corrosion Resistance ◽  
Electron Microscope ◽  
Friction Coefficient ◽  
Ceramic Coating ◽  
Ceramic Coatings ◽  
Oxidation Method ◽  
Polarization Test ◽  
Micro Arc Oxidation ◽  
Scanning Electron

Ceramic coatings were prepared on ZM5 magnetism substrate by micro-arc oxidation method with and without magnetism filed in silicate electrolyte. The morphology of the MAO coatings was investigated by scanning electron microscope (SEM). The friction coefficient of the MAO coatings prepared with magnetism is about 0.2 and more stable than the coatings prepared without magnetism. The polarization test indicated that the coating prepared with magnetism has better corrosion resistance.

Properties of Conversion Coating of Magnesium Alloys by a Phosphate-Permanganate Solution

2005 ◽  
Vol 488-489 ◽  
pp. 665-668 ◽  
Author(s):  
Shu Sen Wu ◽  
Ming Zhao ◽  
Ji Rong Luo ◽  
You Wu Mao
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloys ◽  
Adhesion Force ◽  
Conversion Coating ◽  
Resistance Test ◽  
Az91d Alloy ◽  
Conversion Coatings ◽  
Good Adhesion ◽  
Better Than

A chromium-free conversion coating for AZ91D magnesium alloys has been obtained by using a phosphate-permanganate solution. Examinations have been carried out on the conversion coating for morphology, composition, adhesion force and corrosion resistance. Results show that the conversion coatings are relatively uniform and continuous, with thickness from 7µm to 10µm. They exhibit good adhesion to matrix and have some non-penetrate tiny holes on the surface. The main elements of the conversion coating of AZ91D alloy are Mg、O、P、K、Al、Mn. Results of corrosion resistance test indicate that the corrosion resistance of the conversion coating by phosphate-permanganate solution is in match to that of the conversion coating formed in a chromate solution, but for the corrosion resistance after painting, the former is better than the later.

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