Publicaties

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Operando odd random phase electrochemical impedance spectroscopy (ORP-EIS) for in-situ monitoring of the Zr-based conversion coating growth in the presence of (in)organic additives Vrije Universiteit Brussel

Meisam Dabiri Havigh, Mohaddese Nabizadeh, Benny Wouters, Noel Hallemans, Tom Hauffman, John Lataire, Annick Hubin, Herman Terryn
Operando odd random phase electrochemical impedance spectroscopy (ORP-EIS) is introduced as an in-situ monitoring tool to directly monitor the conversion treatment of zinc in a hybrid Zr-based solution containing aminosilane and Cu additives. SEM and EDX are applied to investigate the morphology and elemental composition of the oxide film. Results show that the operando ORP-EIS provides an opportunity to investigate the growth of the conversion ...

FEM modelling to predict spatiotemporally resolved water uptake in organic coatings: Experimental validation by odd random phase electrochemical impedance spectroscopy measurements Vrije Universiteit Brussel

Mats Meeusen, Joost van dam, Negin Madelat, Ehsan Jalilian, Benny Wouters, Tom Hauffman, Guy Van Assche, Arjan J. M. C. Mol, Annick Hubin, Herman Terryn, et al.
water
uptake in organic coatings. To this aim, we start from a physical model, where not only Fickian diffusion of
water is taken into account but also the adsorption/desorption reaction of water on the polymer matrix. Starting
from a number of important coating properties and crucial model parameters, derived from gravimetric and
Fourier transform infrared (FTIR) measurements as the model input, the local water concentration ...

Surface modification of biodegradable Mg alloy by adapting µEDM capabilities with cryogenically-treated tool electrodes Vrije Universiteit Brussel

Rahul Davis, Abhishek Singh, Kishore Debnath, Anup Kumar Keshri, Paulo Soares, Luciane Sopchenski Santos, Herman Terryn, Ved Prakash

Biomaterials are engineered to develop an interaction with living cells for therapeutic and diagnostic purposes. The last decade reported a tremendously rising shift in the requirement for miniaturized biomedical implants exhibiting high precision and comprising various biomaterials such as non-biodegradable titanium (Ti) alloys and biodegradable magnesium (Mg) alloys. The excellent mechanical properties and lightweight characteristics of Mg ...

Study on the roles of bisulfite in the stress corrosion cracking of 7050-T7451 aluminum alloy in the thin electrolyte layer environment Vrije Universiteit Brussel

Mingtao Wang, Liwei Wang, Wendi Yang, Yuxi Liu, Herman Terryn

Effect of bisulfite (HSO3-) on the stress corrosion cracking (SCC) behavior of 7050-T7451 aluminum alloy in the thin electrolyte layer environment in the presence of Cl- is investigated. Addition of HSO3- inhibits the corrosion initiation but promotes the corrosion propagation and hydrogen uptake. With a quantitative calculation, the HSO3- is demonstrated to significantly facilitate the synergistic effect between stress, corrosion, and ...

Identification of carbon-containing phases in electrodeposited hard Fe–C coatings with intentionally codeposited carbon Vrije Universiteit Brussel

Kristof Marcoen, Mélanie Gauvin, Ansbert De Cleene, Jacob Obitsø Nielsen, Kitty Baert, Herman Terryn, J. De Strycker, Tom Hauffman, Karen Pantleon

Electrodeposition from an environmentally friendly iron sulfate electrolyte with citric acid as carbon source has gained attention recently, because of excellent mechanical properties of the resulting Fe–C coatings with intentionally codeposited high-carbon concentrations. While being very attractive as protective coatings and sustainable alternatives for hard chrome coatings, comprehensive understanding of the coatings' chemical constitution ...

Pre-eruptive storage conditions and magmatic evolution of the Bora-Baricha-Tullu Moye volcanic system, Main Ethiopian Rift Vrije Universiteit Brussel

A. Z. Tadesse, Karen Fontijn, L. Caricchi, F. Bégué, S. Gudbrandsson, V. C. Smith, P. Gopon, Vinciaene Debaille, Priya Laha, Herman Terryn, et al.

Bora-Baricha-Tullu Moye is a Late Quaternary volcanic system in the Main Ethiopian Rift, characterised by products of both explosive and effusive volcanic eruptions. The petrological and geochemical characteristics of the volcanic products are investigated using a combination of petrography, major and trace element whole rock analyses and in-situ major element analyses of phenocryst phases, matrix glass and melt inclusions. The bulk rock ...

Heat treatment for metal additive manufacturing Vrije Universiteit Brussel

Majid Laleh, Esmaeil Sadeghi, Reynier I. Revilla, Qi Chao, Nima Haghdadi, Anthony Hughes, Wei Xu, Iris De Graeve, Ma Qian, Ian Gibson, et al.
Metal additive manufacturing (AM) refers to any process of making 3D metal parts layer-upon layer via the interaction between a heating source and feeding material from a digital design model. The rapid heating and cooling attributes inherent to such an AM process result in het erogeneous microstructures and the accumulation of internal stresses. Post-processing heat treatment is often needed to modify the microstructure and/or alleviate ...

Differentiating between the diffusion of water and ions from aqueous electrolytes in organic coatings using an integrated spectro-electrochemical technique Vrije Universiteit Brussel

Negin Madelat, Benny Wouters, Ehsan Jalilian, Guy Van Assche, Annick Hubin, Herman Terryn, Tom Hauffman

In this work, the separate diffusion of water and ions through a polyethylene glycol diacrylate (PEGDA) coating was characterized using an integrated spectro-electrochemical technique. The ions ingress front position profile along the thickness of the coating was derived from fitting odd random phase electrochemical impedance spectroscopy (ORP-EIS) data using a physically relevant electrochemical equivalent circuit (EEC). The arrival time of ...

Investigation of hybrid Zr-aminosilane treatment formation on zinc substrate and comparison to advanced high strength stainless steel Vrije Universiteit Brussel

Mohaddese Nabizadeh, Kristof Marcoen, El Amine Mernissi Cherigui, Meisam Dabiri Havigh, Thomas kolberg, Daniel Schatz, Herman Terryn, Tom Hauffman

This research investigates the deposition mechanism of a hybrid Zr-aminosilane conversion coating as a replacement for the conventional pretreatment systems on a zinc substrate. The traditional Zr-based conversion treatment has been optimized by the addition of both Cu as an accelerator and aminosilane as an adhesion promotor. The deposition mechanism was unraveled using complementary surface analytical techniques such as XPS, FEG-AES, EDX, ...

Methods—On the Application of Ambient Scanning Kelvin Probe Force Microscopy to Understand Micro-Galvanic Corrosion Phenomena: Interpretation and Challenges Vrije Universiteit Brussel

Reynier I. Revilla
The capabilities of scanning Kelvin probe force microscopy (SKPFM) to directly measure local Volta potential differences with relatively high spatial resolution has made it a very popular technique to assess the relative nobility of intermetallic phases and therefore to understand corrosion susceptibility and microgalvanic corrosion activity in several alloys. However, the direct correlation between galvanic corrosion activity and Volta ...