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Author

Willem J. Quadakkers

Other affiliations: Siemens
Bio: Willem J. Quadakkers is an academic researcher from Forschungszentrum Jülich. The author has contributed to research in topics: Oxide & Alloy. The author has an hindex of 55, co-authored 225 publications receiving 8960 citations. Previous affiliations of Willem J. Quadakkers include Siemens.
Topics: Oxide, Alloy, Chromia, Chromium, Coating


Papers
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Journal ArticleDOI
TL;DR: For planar solid oxide fuel cell (SOFC) designs, ceramic as well as metallic materials are being considered as construction materials for the interconnectors as discussed by the authors, however, the specific combination of properties required for a SOFC interconnector will necessitate the development of a new, specifically designed steel or the modification of an existing commercial st...
Abstract: For planar solid oxide fuel cell (SOFC) designs, ceramic as well as metallic materials are being considered as construction materials for the interconnectors. Compared to the ceramics, mostly compounds on the basis of La-chromite, metallic materials have the advantage of easier fabricability, lower costs as well as higher heat and electrical conductivity. Based on the requirements in respect to oxidation resistance, low thermal expansion coefficient and electrical conductivity of surface oxide scales, Cr-based alloys and high-Cr ferritic steels seem to be the most promising metallic interconnector materials. Whereas Cr-based alloys have recently especially been developed for SOFC application, a large number of ferritic steels are commercially available in a wide range of compositions. However, it seems that the specific combination of properties required for a SOFC interconnector will necessitate the development of a new, specifically designed steel or the modification of an existing commercial st...

369 citations

Journal ArticleDOI
TL;DR: In this paper, the short term (∼100h) oxidation behavior of 9%Cr steel P91 was studied at 650°C in N 2 -O 2 -H 2 O gas mixtures containing a relatively low oxygen level of 1%.

277 citations

Journal ArticleDOI
TL;DR: In this paper, the state of the art on the oxidation of TiAl is reviewed and compared to the oxide of conventional Fe, Ni and Co alloys, and three different scale structures can be distinguished as functions of time or scale thickness.
Abstract: The paper critically reviews the state of the art on the oxidation of TiAl. At the beginning differences compared to the oxidation of conventional Fe, Ni and Co alloys are discussed. The Knowledge of the TiAlO phase diagram as a basis for an understanding of the processes occurring during oxidation is very incomplete. Three different scale structures can be distinguished as functions of time or scale thickness. In the sub-surface zone two phases with high oxygen solubilities can be identified after a certain time. These phases do not follow from the existing phase diagram. Nitrogen can have two different effects depending on the time it is added to the oxidation environment. The micro-structure also affects the oxidation behaviour significantly, so this effect can lead to a misinterpretation of the influence of other parameters such as alloying elements. The influence of alloying elements is not yet understood. Mechanical loading leads to scale cracking, however, the system has a significant scale repair capacity, though about twothirds of the scale grows by inwards transport. Grundlagen der TiAl-Oxidation – Eine kritische Ubersicht Die Arbeit gibt eine kritische Betrachtung der Kenntnisse uber die Oxidation von TiAl. Einleitend wird auf Unterschiede im Vergleich zur Oxidation konventioneller Fe. Ni und Co-Legierungen hingewiesen. Die derzeitigen Kenntnisse uber das Phasendiagramm TiAlO als Basis fur das Verstandnis der bei der Oxidation ablaufenden Prozesse sind sehr unvollstandig. Im Aufbau der Oxidschicht konnen drei Grenzfalle unterschieden werden, die als Funktion der Zit nacheinander durchlaufen werden. Stickstoff kann offensichtlich zwei Effekte auslosen, abhangig vom Zeitpunkt der Zugabe zum Reaktionsgas. Die Mikrostruktur kann einen starken Einflus haben und andere Einflusse wie die von Legierungselementen verdecken. Der Einflus von Legierungselementen wird derzeit nicht verstanden. Damit sind auch keine sinnvollen Vorhersagen moglich. Mechanische Belastungen verursachen ein Aufreisen der Oxidschicht, die jedoch eine beachtliche Ausheilfahigkeit fur Oxidschichtrisse hat.

265 citations

Journal ArticleDOI
TL;DR: In this paper, the vaporization of Cr species of a variety high chromium alloys was studied at 800 °C in air using the transpiration method, and the measured release of the different alloys were correlated with the formed outer oxide scales.

264 citations

Journal ArticleDOI
TL;DR: In this paper, high-Cr ferritic model steels containing various additions of the refractory elements Nb and/or W were studied with respect to oxidation behaviour (hot) tensile properties, creep behaviour and high-temperature electrical conductivity of the surface oxide scales.

217 citations


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Book
31 Jul 2008
TL;DR: In this paper, the physical metallurgy of nickel and its alloys is discussed and single crystal superalloys for blade applications for turbine disc applications are discussed. And the role of coatings is discussed.
Abstract: 1. Introduction 2. The physical metallurgy of nickel and its alloys 3. Single crystal superalloys for blade applications 4. Superalloys for turbine disc applications 5. Environmental degradation: the role of coatings 6. Summary and future trends.

3,067 citations

Journal ArticleDOI
TL;DR: These advances have led to dozens of active SOFC development programs in both stationary and mobile power and contributed to commercialization or development in a number of related technologies, including gas sensors, solid-state electrolysis devices, and iontransport membranes for gas separation and partial oxidation.
Abstract: Recent worldwide interest in building a decentralized, hydrogen-based energy economy has refocused attention on the solid oxide fuel cell (SOFC) as a potential source of efficient, environmentally friendly, fuel-versatile electric power. Due to its high operating temperature, the SOFC offers several potential advantages over polymer-based fuel cells, including reversible electrode reactions, low internal resistance, high tolerance to typical catalyst poisons, production of high-quality waste heat for (among other uses) reformation of hydrocarbon fuels, as well as the possibility of burning hydrocarbon fuels directly. Today, SOFCs are much closer to commercial reality than they were 20 years ago, due largely to technological advances in electrode material composition, microstructure control, thin-film ceramic fabrication, and stack and system design. These advances have led to dozens of active SOFC development programs in both stationary and mobile power and contributed to commercialization or development in a number of related technologies, including gas sensors,1 solid-state electrolysis devices,2 and iontransport membranes for gas separation and partial oxidation.3 Many reviews are available which summarize the technological advances made in SOFCs over the last 15-35 yearssreaders who are primarily interested in knowing the state-of-the art in materials, design, and fabrication (including the electrodes) are encouraged to consult these reviews.4-12 This review focuses on the factors governing SOFC cathode performancesadvances we have made over † Dedicated to Brian Steele, 1929-2003. Researcher, Entrepreneur, Consensus Seeker. 4791 Chem. Rev. 2004, 104, 4791−4843

2,033 citations

Journal ArticleDOI
TL;DR: There remains growing interest in magnesium (Mg) and its alloys, as they are the lightest structural metallic materials Mg alloys have the potential to enable design of lighter engineered systems, including positive implications for reduced energy consumption as mentioned in this paper.

1,173 citations

Journal ArticleDOI
TL;DR: In this paper, the authors provide a comprehensive review with respect to the structure, chemistry, design and selection of materials, underlying mechanisms, and performance of each SOFC component, and it opens up the future directions towards pursuing SOFC research.

1,119 citations

Journal ArticleDOI
TL;DR: A review of the published knowledge on the oxy-fuel process can be found in this paper, focusing particularly on the combustion fundamentals, i.e. flame temperatures and heat transfer, ignition and burnout, emissions, and fly ash characteristics.

1,042 citations