The Experts below are selected from a list of 107880 Experts worldwide ranked by ideXlab platform
Johannes M. C. Mol - One of the best experts on this subject based on the ideXlab platform.
-
The influence of a Zr-based Conversion Treatment on interfacial bonding strength and stability of epoxy coated carbon steel
Progress in Organic Coatings, 2017Co-Authors: M. Sababi, Herman Terryn, Johannes M. C. MolAbstract:The effect of a zirconium (Zr)-based preTreatment on interfacial bonding properties of a fusion bonded epoxy (FBE) coating on carbon steel is investigated. The initiation and kinetics of delamination of epoxy coatings applied on differently pretreated carbon steel surfaces is studied with scanning Kelvin probe (SKP). In-situ attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) is applied to study interfacial coating-oxide chemistry changes upon electrolyte diffusion towards the buried interface. Corresponding coating degradation is analyzed with the use of electrochemical impedance spectroscopy (EIS). pull off experiments showed a clear beneficial effect of the Zr-based preTreatment improving the dry and wet adhesion properties of the fusion bonded epoxy coating to the carbon steel surface particularly upon exposure to wet and corrosive conditions. This increase in interfacial bonding stability is confirmed by the ATR-FTIR and EIS experiments and delayed and slower delamination was observed in the SKP measurements.
-
An in situ study of zirconium-based Conversion Treatment on zinc surfaces
Applied Surface Science, 2015Co-Authors: Peyman Taheri, Herman Terryn, Priya Laha, Johannes M. C. MolAbstract:Abstract This study is focused on the deposition process of zirconium-based Conversion layers on Zn surfaces. The analysis approach is based on a Kretschmann configuration in which in situ ATR-FTIR spectroscopy is combined with open circuit potential (OCP) and near surface pH measurements. Differently pretreated Zn surfaces were subjected to Conversion Treatments, while the Zr-based deposition mechanism was probed in situ. It was found that the initial hydroxyl fraction promotes the overall Zr Conversion process as the near surface pH values are influenced by the initial hydroxyl fraction. Kinetics of the early surface activation and the subsequent Zr-based Conversion process are discussed and correlated to the initial hydroxyl fractions.
Herman Terryn - One of the best experts on this subject based on the ideXlab platform.
-
The mechanism of thermal oxide film formation on low Cr martensitic stainless steel and its behavior in fluoride-based pickling solution in Conversion Treatment
Corrosion Science, 2021Co-Authors: Mohaddese Nabizadeh, Clément Boissy, Kitty Baert, Steven Goderis, Heidi Ottevaere, Herman Terryn, Tom HauffmanAbstract:Abstract (Attention for corrosion science, the abstract must not exceed more than 100 words) In this research, first a multi-analytical approach was carried out to propose a mechanistic model for the formation of the thermal oxide film on low Cr stainless steel. It describes the effects of kinetically and thermodynamically driven phenomena on the growth of a Fe-Cr complex oxide film at 950℃. Second, the behavior of the thermal oxide film in the presence of fluoride ions, as a relevant pickling agent in Conversion Treatment, was investigated. It was shown that fluoride ions enter the oxide film and form a complex with Fe and preferentially dissolve hematite islands through a complexation mechanism.
-
The influence of a Zr-based Conversion Treatment on interfacial bonding strength and stability of epoxy coated carbon steel
Progress in Organic Coatings, 2017Co-Authors: M. Sababi, Herman Terryn, Johannes M. C. MolAbstract:The effect of a zirconium (Zr)-based preTreatment on interfacial bonding properties of a fusion bonded epoxy (FBE) coating on carbon steel is investigated. The initiation and kinetics of delamination of epoxy coatings applied on differently pretreated carbon steel surfaces is studied with scanning Kelvin probe (SKP). In-situ attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) is applied to study interfacial coating-oxide chemistry changes upon electrolyte diffusion towards the buried interface. Corresponding coating degradation is analyzed with the use of electrochemical impedance spectroscopy (EIS). pull off experiments showed a clear beneficial effect of the Zr-based preTreatment improving the dry and wet adhesion properties of the fusion bonded epoxy coating to the carbon steel surface particularly upon exposure to wet and corrosive conditions. This increase in interfacial bonding stability is confirmed by the ATR-FTIR and EIS experiments and delayed and slower delamination was observed in the SKP measurements.
-
An in situ study of zirconium-based Conversion Treatment on zinc surfaces
Applied Surface Science, 2015Co-Authors: Peyman Taheri, Herman Terryn, Priya Laha, Johannes M. C. MolAbstract:Abstract This study is focused on the deposition process of zirconium-based Conversion layers on Zn surfaces. The analysis approach is based on a Kretschmann configuration in which in situ ATR-FTIR spectroscopy is combined with open circuit potential (OCP) and near surface pH measurements. Differently pretreated Zn surfaces were subjected to Conversion Treatments, while the Zr-based deposition mechanism was probed in situ. It was found that the initial hydroxyl fraction promotes the overall Zr Conversion process as the near surface pH values are influenced by the initial hydroxyl fraction. Kinetics of the early surface activation and the subsequent Zr-based Conversion process are discussed and correlated to the initial hydroxyl fractions.
Jun-yen Uan - One of the best experts on this subject based on the ideXlab platform.
-
Converting waste magnesium scrap into anion-sorptionable nanomaterials: synthesis and characterization of an Mg–Al–Cl hydrotalcite-like compound by hydrolysis and chemical Conversion Treatment in aqueous chloride solutions
RSC Adv., 2014Co-Authors: Yung-feng Lung, Yu-fan Syu, Meng-chang Lin, Jun-yen UanAbstract:Although there have been many reports on the synthesis of hydrotalcite-like compounds (HTlc), none of them have investigated the special case of converting metal waste into anion-sorptionable HTlc. Mg–Al alloy is the most commonly used Mg alloy. Most metallic Mg waste and post-consumer Mg products are, however, currently not recyclable, thus leaving the resources wasted. Here, methods that allow the reuse and recycling of Mg waste are demonstrated, employing a combination of hydrolysis and chemical Conversion Treatment in chloride acidic solutions that corrode metallic waste to develop Mg–Al–Cl HTlc. The study can convert bulk-type magnesium waste into nanosized Mg–Al–Cl HTlc powder. For fine flake-type magnesium waste, Mg–Al–Cl HTlc film can directly form on the surface of the flake. All the synthesized HTlcs have nanosized microstructures, being able to function to take up most of the fluoride and sulfate anions from waste water.
-
Enhancement of corrosion resistance of Mg-9 wt.% Al-1 wt.% Zn alloy by a calcite (CaCO3) Conversion hard coating
Corrosion Science, 2010Co-Authors: X.l. Pan, Jun-yen UanAbstract:Abstract A calcite (CaCO 3 ) coating on Mg alloy, formed by chemical Conversion Treatment, was investigated. Aqueous Ca 2 + / HCO 3 - with Ca 2+ concentration of ∼220 ppm was employed in the chemical Conversion Treatment. Cross-sectional microstructures of the coated sample after 2 h of Treatment revealed a two-layer coating structure. The corrosion current density ( I corr ) of the coated sample was approximately two orders of magnitude lower than that of the untreated sample. Electrochemical impedance spectroscopy (EIS) and an appropriate equivalent circuit suggested that each of the layers of the two-layer coating effectively protects Mg alloy against corrosion.
-
formation of mg al hydrotalcite Conversion coating on mg alloy in aqueous hco3 co32 and corresponding protection against corrosion by the coating
Corrosion Science, 2009Co-Authors: Junkai Lin, Jun-yen UanAbstract:Abstract An environmentally clean method is studied for synthesizing a Conversion coating on Mg alloy in aqueous HCO 3 - / CO 3 2 - at 50 °C. A precursor layer was firstly formed on AZ91D sample. The precursor layer transformed into a crystallized Mg,Al-hydrotalcite when the sample was continuously immersed in the bath until the bath changed from acidic to alkaline. A rapid Conversion Treatment was, therefore, developed: it involved maintaining the pH under 6 for precursor layer formation and then increasing it to 11.5 to form crystallized Mg,Al-hydrotalcite coating. No corrosion spot on the Mg,Al-hydrotalcite-coated sample was observed after a 72-hour salt spray test.
John M. Sykes - One of the best experts on this subject based on the ideXlab platform.
-
Effects of thermal and mechanical Treatments on a titanium-based Conversion coating for aluminium alloys
Corrosion Science, 2004Co-Authors: Mascha A. Smit, G.m. Scamans, J.a. Hunter, J.d.b. Sharman, John M. SykesAbstract:Abstract The influence of mechanical deformation and heating on the protective performance of a chromium-free Conversion Treatment for aluminium alloys has been assessed by polarisation and AC impedance measurements. Protection is unlikely to be seriously compromised by typical production operations.
-
Manganese based Conversion Treatment
Surface Engineering, 1999Co-Authors: I. Danilidis, John M. Sykes, J.a. Hunter, G.m. ScamansAbstract:Environmental concerns relating to chromate containing Conversion Treatments employed for the protection of aluminium alloys from corrosion have led to a search for their replacement. In this study, an alternative manganese based Treatment has been examined. Its properties have been examined using electrochemical, electron microscopical, and spectroscopical techniques. Promising results have been obtained and further research is being carried out to provide a better understanding of the mechanism responsible for its good performance.
Peyman Taheri - One of the best experts on this subject based on the ideXlab platform.
-
An in situ study of zirconium-based Conversion Treatment on zinc surfaces
Applied Surface Science, 2015Co-Authors: Peyman Taheri, Herman Terryn, Priya Laha, Johannes M. C. MolAbstract:Abstract This study is focused on the deposition process of zirconium-based Conversion layers on Zn surfaces. The analysis approach is based on a Kretschmann configuration in which in situ ATR-FTIR spectroscopy is combined with open circuit potential (OCP) and near surface pH measurements. Differently pretreated Zn surfaces were subjected to Conversion Treatments, while the Zr-based deposition mechanism was probed in situ. It was found that the initial hydroxyl fraction promotes the overall Zr Conversion process as the near surface pH values are influenced by the initial hydroxyl fraction. Kinetics of the early surface activation and the subsequent Zr-based Conversion process are discussed and correlated to the initial hydroxyl fractions.