scholarly journals PLASMA SPRAYED AL ₂O₃-13 WT.%TIO₂ COATING SEALED WITH ORGANIC-INORGANIC HYBRID AGENT AND ITS CORROSION RESISTANCE IN ACID ENVIRONMENT

2016 ◽  
pp. 254-261 ◽  
Author(s):  
Zehua Zhou
Keyword(s):  
Corrosion Resistance ◽  
Inorganic Hybrid ◽  
Acid Environment ◽  
Hybrid Agent ◽  
Plasma Sprayed

Microstructure and Corrosion Resistance of Plasma Sprayed Fe-Based Alloy Coating as an Alternative to Hard Chromium

2010 ◽  
Vol 20 (5) ◽  
pp. 1063-1070 ◽  
Author(s):  
Wenhuan Lu ◽  
Yuping Wu ◽  
Jingjing Zhang ◽  
Sheng Hong ◽  
Jianfeng Zhang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Alloy Coating ◽  
Hard Chromium ◽  
Plasma Sprayed

Laser Sintering of Nano-Al2O3 Powders on Plasma Sprayed Ceramic Based Coatings

2007 ◽  
Author(s):  
Lida Shen ◽  
Yinhui Huang ◽  
Zongjun Tian ◽  
Guoran Hua
Keyword(s):  
Wear Resistance ◽  
Corrosion Resistance ◽  
Plasma Spraying ◽  
Bond Coat ◽  
Continuous Wave ◽  
Ceramic Coatings ◽  
Laser Sintering ◽  
Al2o3 Ceramic ◽  
Plasma Sprayed ◽  
Steel Substrates

This paper describes an investigation of nano-Al2O3 powders reinforced ceramic coatings, which has included NiCrAl and Al2O3+13%wt.TiO2 coats pre-produced by atmosphere plasma spraying, implemented by laser sintering. Commercial NiCrAl powders were plasma sprayed onto 45 Steel substrates to give a bond coat with thickness of ∼100μm. The 600μm thick Al2O3+13%wt.TiO2 based coating was also plasma sprayed on top of the NiCrAl bond coat. With 2.5kw continuous wave CO2 laser, nano-Al2O3 ceramic powders were laser sintered on the based Coatings. The micro structure and chemical composition of the modified Al2O3+13%wt.TiO2 coatings were analyzed by such detection devices as scanning electronic microscope (SEM) and x-ray diffraction (XRD). Microhardness, wear resistance and corrosion resistance of the modified coatings were also tested and compared with that of the unmodified. The results show that the crystal grain size of Al2O3 had no obvious growth. In addition, due to the nanostructured Al2O3 ceramic phases, the coatings exhibited higher microhardness, better wear resistance and corrosion resistance than those unmodified counterparts. The complex process of plasma spraying with laser sintering as a potential effective way of the application of ceramic nano materials was also simply discussed and summarized in the end.

Sealing Treatment of Plasma Sprayed Cr3C2-NiCr/Al2O3-TiO2 Coating by Aluminum Phosphate Sealant Containing Al2O3 Nanoparticles

2021 ◽  
Author(s):  
Tuan Nguyen Van ◽  
Tuan Anh Nguyen ◽  
Ha Pham Thi ◽  
Ly Pham Thi ◽  
Phuong Nguyen ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Aluminum Phosphate ◽  
Al2o3 Nanoparticles ◽  
Treatment Efficiency ◽  
Typical Structure ◽  
Sprayed Coating ◽  
Plasma Sprayed ◽  
Sealing Treatment ◽  
Sprayed Coatings

Abstract A typical structure of thermal spray coatings consisted of molten particles, semi-molten particles, oxides, pores and cracks. These factors caused the porosity of sprayed coatings, leading to a great influence on the coating properties, especially their wear-corrosion resistance. In this study, a post-spray sealing treatment of Cr3C2-NiCr/Al2O3-TiO2 plasma sprayed coatings was carried out, then their corrosion properties were evaluated, before and after the treatment. For sealing process, aluminum phosphate (APP) containing aluminum oxide (Al2O3) nanoparticles (~10 nm) was used. The permeability of APP into the sprayed coating was analyzed by scanning electron microscopy coupled with energy dispersive spectroscopy (SEM-EDS). The treatment efficiency for porosity and corrosion resistance of sprayed coatings were evaluated by electrochemical measurements, such as the potentiodynamic polarization and electrochemical impedance spectroscopy. In addition, the wear-corrosion resistance of the sealed coating was examined in 3.5 wt.% NaCl circulation solution containing 0.25 wt.% SiO2 particles. The obtained results showed that APP penetrated deeply through the sprayed coating. The incorporation of Al2O3 nanoparticles into APP sealant enhanced the treatment efficiency of porosity for sprayed coating. The effect of the post-treatment on corrosion protection of the sprayed coating has been discussed.

Composite ZrO2-Based Cermet Material Modified with Mo

2015 ◽  
Vol 237 ◽  
pp. 3-8 ◽  
Author(s):  
Adriana Wrona ◽  
Kinga Czechowska ◽  
Małgorzata Osadnik ◽  
Małgorzata Kamińska ◽  
Marcin Lis ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Plasma Spraying ◽  
Alloy Coating ◽  
Metallic Material ◽  
Cermet Material ◽  
Powder Composites ◽  
Annealing Procedure ◽  
Plasma Sprayed ◽  
Structure And Microstructure

The work presents studies of a new ceramic-metallic material. The base is a ZrO2-Mo cermet which is modified with metallic Mo or Mo85Re15 alloy coating. The structure and microstructure of Mo85Re15 alloy powders and the composite were characterized. The annealing procedure was found to influence phase composition of powder composites but not their morphology. The plasma sprayed powders, both metallic and alloyed, form coatings that adhere well to the cermet substrate. The coatings show a better homogeneity in comparison to powders and more favourable phase composition.Keywords: cermets, plasma spraying, corrosion resistance

Analysis of corrosion behaviour and surface properties of plasma-sprayed composite coating of hydroxyapatite–tantalum on biodegradable Mg alloy ZK60

2019 ◽  
Vol 53 (19) ◽  
pp. 2661-2673 ◽  
Author(s):  
Balraj Singh ◽  
Gurpreet Singh ◽  
Buta Singh Sidhu
Keyword(s):  
Corrosion Resistance ◽  
Surface Properties ◽  
Corrosion Behaviour ◽  
Surface Hardness ◽  
Mg Alloy ◽  
Hydroxyapatite Coating ◽  
Hydroxyapatite Coatings ◽  
Plasma Sprayed ◽  
Incremental Increase

Magnesium (Mg) and its alloys are promising candidates for biodegradable bio-implants. However, the excessive corrosion in the physiological environment and subsequent decline in the mechanical integrity of Mg and its alloys have limited their utility as biomaterials. In the present study, an attempt has been made to improve the corrosion resistance of Mg alloy ZK60 plasma sprayed with tantalum (Ta)-reinforced hydroxyapatite coating. The experiment was conducted with three varied levels, i.e. 10, 20 and 30 weight percent (wt%) of Ta-content in hydroxyapatite coating. The coatings were characterized and in vitro corrosion behaviour was investigated by electrochemical measurements in Ringer's solution along with the analysis of surface properties. The corrosion resistance of the Mg alloy increased with the incremental increase in Ta reinforcement in hydroxyapatite coating. An increase in the protection efficiency was analysed for the Ta-reinforced hydroxyapatite coatings (∼10%, 18% and 23% for hydroxyapatite-10Ta, hydroxyapatite-20Ta and hydroxyapatite-30Ta, respectively) as compared to the pure hydroxyapatite coating. The hydroxyapatite coating effectively increased the surface hardness of the Mg alloy and Ta reinforcement further enhanced it. Surface roughness decreased with the incremental increase in Ta-content in hydroxyapatite coating. Wettability analysis revealed the hydrophilic nature of pure hydroxyapatite and Ta-reinforced hydroxyapatite coatings. The results of the study suggest that the proposed Ta reinforcement in hydroxyapatite is potentially important for biodegradable Mg bio-implants.

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