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December 2012 JOM Examines High Temperature Materials |
Robust Preview of TMS2013 also Featured
Posted on: 11/23/2012 12:00:00 AM... In-depth coverage of key programming events and educational opportunities for the TMS 2013 Annual Meeting and Exhibition (TMS2013), set for March 3-7 in San Antonio, Texas, highlights JOM's December 2012 issue. Relevant articles include an overview of conference highlights, “TMS 2013 Convenes the Continuum of Materials Science and Engineering.” Among other events and activities, this feature includes details on the Aluminum Keynote Session, Nickel-Cobalt Symposium, continuing education opportunities, and programming for young professionals. “Materials Science
Thought Leaders Examine Global R&D Trends” offers a preview of a signature event for TMS2013—
the Acta Materialia Materials and Society Award Symposium, organized in honor of Jeffrey Wadsworth, president and chief executive officer, Battelle Memorial Institute. And, “REWAS 2013: Enabling Materials Resources Sustainability” outlines the topics and issues that will be explored during this special TMS2013 symposium. For additional information on TMS2013 and to register, go to the conference website.
The technical theme for the December issue is High Temperature Materials, which is examined within three technical topics. A synopsis of the 12 papers and three commentaries is provided below. To read the entire JOM issue online, to go Springerlink.
LIGHT WATER REACTOR FUELS
Materials Issues Related to the Use of Light Water Reactor Fuels
Dennis D. Keiser
This commentary summarizes the collection of JOM papers within this technical topic, sponsored by the TMS Nuclear Materials Committee. The compilation touches on recent developments in the areas of nuclear fuels and materials development, processing, characterization, testing, and performance in the context of advancing the use of nuclear energy.
Recent Results of Microstructural Characterization of Irradiated Light Water Reactor Fuels using Scanning and Transmission Electron Microscopy
T. Wiss, H. Thiele, A. Janssen, D. Papaioannou, V.V. Rondinella, and R.J.M. Konings
Recent electron microscopy investigations are presented with emphasis on properties related to the safe extended operation of nuclear fuel. In particular, this paper considers the formation of the high burnup structure (HBS), the prevailing microstructural aspects associated to spent fuel aging, and the release of fission products under accidental condition. Examples of microstructures associated to transient-tested samples, but also to very high burnup fuel or heterogeneous MOX, are presented together with results on damage formation in UO2 samples doped with 238Pu to study the specific effect of alpha-damage on the microstructure during the cooling/storage time of irradiated fuel. Examples of single effect studies (e.g. on the behavior of tellurium, a typical volatile fission product) using ion-implantations are also presented.
Transient Testing of Nuclear Fuels and Materials in United States
Daniel M. Wachs
The United States has established that transient irradiation testing is needed to support advanced LWR fuel development. The US Department of Energy (DOE) has initiated an effort to re-establish this capability through the restart of the Transient Reactor Test (TREAT) facility located at the Idaho National Laboratory. This effort will also include the development of specialized test vehicles to support stagnant capsule and flowing loop tests as well as the enhancement of post-irradiation examination capabilities and remote device assembly capabilities at the Hot Fuel Examination Facility (HFEF). It is anticipated that the capability will be available to support testing by 2018, as required to meet the DOE goals for the development of accident tolerant LWR fuel designs.
Hydride Formation in Zirconium Alloys
Arthur T. Motta and Long-Qing Chen
The ingress of hydrogen during corrosion in service can degrade the mechanical properties of zirconium alloy nuclear fuel cladding because of the formation of brittle hydrides. The formation of these hydrides is reviewed in light of recent synchrotron radiation experimental results and phase field modeling computational results that provide new insight on the process.
Effect of Travel Speed and Beam Focus on Porosity in Alloy 690 Laser Welds
Julie D. Tucker, Terrance K. Nolan, Anthony J. Martin, and George A. Young
Advances in laser welding technology, including fiber optic delivery and high power density, are increasing the applicability of this joining technique. The inherent benefits of laser welding include small heat affected zones, minimal distortion, and limited susceptibility to cracking. These advantages are of special interest to next generation nuclear power systems where welding solute rich alloys is expected to increase Alloy 690 (A690) is an advanced corrosion resistant structural material used in many replacement components and in construction of new commercial power plants. However, application of A690 is hindered by its difficult weldability using conventional arc welding and laser welding is a promising alternate. This work studies the effects of travel speed and beam focus on porosity formation in partial penetration, autogenous A690 laser welds.
Assessment of Titanium Aluminide Alloys for High-Temperature Nuclear Structural Applications
Hanliang Zhu, Tao Wei, David Carr, Robert Harrison, Lyndon Edwards, Wolfgang Hoffelner, Dongyi Seo, and Kouichi Maruyama
Titanium aluminide (TiAl) alloys exhibit high specific strength, low density, good oxidation, and corrosion and creep resistance at elevated temperatures, making them good candidate materials for aerospace and automotive applications. TiAl alloys also show excellent radiation resistance and low neutron activation, and can be developed to have various microstructures, allowing different combinations of properties for various extreme environments. This paper reviews the microstructure, creep, radiation and oxidation properties of TiAl alloys in comparison with other nuclear structural materials to assess the potential of TiAl alloys as candidate structural materials for future nuclear applications.
GAS-ALLOY INTERACTIONS AT ELEVATED TEMPERATURES
Gas-Alloy Interactions at Elevated Temperatures
Raymundo Arroyave and Michael Gao
This commentary provides an overview of the papers collected within this technical topic that illustrate the application of different theoretical, computational, and experimental techniques to investigate gas-alloy interactions.
Investigation of Complex Iron Surface Catalytic Chemistry Using the ReaxFF Reactive Force Field Method
Chengu Zou and Adri van Duin
To demonstrate the feasibility of classical reactive dynamics for studying complex surface chemistry, a series of five reactive molecular dynamics (MD) simulations were performed addressing the carbon monoxide methanation and the hydrocarbon chain initiation using ReaxFF reactive force field method. These simulations indicate the possible cooperation among different mechanisms and prove the serviceability of the ReaxFF method for studying the complex heterogeneous catalytic system. The authors were also able to evaluate the accuracy of the current ReaxFF Fe/C/O/H description, providing crucial information regarding areas where further improvement is required.
Calphad Modeling of Metal–Hydrogen Systems: A Review
J.-M. Joubert
This paper reviews the metal-hydrogen systems modeled or investigated with the Calphad method. The specific features of metal-hydrogen systems in relation with Calphad modeling are detailed and the problems and needs related to the description of such systems are highlighted.
Hydrogen Effervescence from Aluminum Alloy Melts
Aleksandar M. Mitrašinovic and Ryan D’Souza
With expansion of integrated computational materials engineering, new mathematical models are required for assessment of processes which traditionally were manually monitored on factory production floors. In this paper, the Richards logistic function is used to describe total amount of porosity in as-cast aluminum alloy sample after treatment under near vacuum and atmospheric pressures. The authors determined that the Richards logistic function can be used instead of traditional low order mathematical equations to predict threshold limit and amount of porosity in solidified aluminum alloys by assessing hydrogen concentration in aluminum alloy melts.
CORROSION AT HIGH TEMPERATURES
Corrosion at High Temperatures
Vilupanur A. Ravi
This commentary introduces the papers presented within this technical topic on different aspects of high temperature corrosion. They are also relevant to the “Gas-Alloy Interactions at Elevated Temperatures” technical topic included in this issue of JOM.
Mechanistic-Based Lifetime Predictions for High-Temperature Alloys and Coatings
B.A. Pint, S. Dryepondt, A. Rouaix-Vande Put, and Y. Zhang
Increasing efficiency is a continuing goal for all forms of power generation, from conventional fossil fuels to new renewable sources. However, increasing the process temperature to increase efficiency leads to faster degradation rates and more components with corrosion-limited lifetimes. At the highest temperatures, oxidation-resistant alumina-forming alloys and coatings are needed for maximum lifetimes. Lifetime models accurate over the extended application durations are not currently available for a wide range of candidates and conditions. Increased mechanistic understanding and relevant long-term data sets will assist in model development and validation. In this paper, current progress is outlined for applying a reservoir-type model to Fe-base alloys and coatings.
Metal Dusting: Catastrophic Corrosion by Carbon
David J. Young and Jianqiang Zhang
This paper reviews recent work on metal dusting and covers the mass transfer—principally carbon diffusion—and graphite nucleation processes involved. A clear distinction emerges between ferritic alloys, which form cementite and precipitate graphite within that carbide, and austenitics which nucleate graphite directly within the metal. The latter process is facilitated by the strong orientation relationship between the graphite and fcc lattices. Strategies for the control of dusting are briefly outlined.
High-Temperature Dual-Atmosphere Corrosion of Solid-Oxide Fuel Cell Interconnects
Paul Gannon and Roberta Amendola
This article reviews high-temperature dual-atmosphere corrosion phenomena and discusses implications for SOFC stacks, related applications, and future research.
Oxidation Characteristics of Magnesium Alloys
Frank Czerwinski
Magnesium oxide, MgO, has a number of features which make it useful in a variety of applications, but does not offer protection to magnesium alloys against thermal oxidation. While additions of common alloying elements generally increase the oxidation rate of Mg-based alloys, doping of MgO with reactive-element atoms essentially improves its protective behavior
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