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Title Antepara, I.; Villarreal, I.; Rodriguez-Martinez, L.M.; Lecanda, N.; Castro, U.; Laresgoiti, A
Year Evaluation of ferritic steels for use as interconnects and porous metal supports in IT-SOFCs
Abbreviated Journal Journal Article
Issue 2005 Keywords Journal of Power Sources
Thesis 151
Place of Publication Language 103-107
Original Title SOFC; ferritic stainless steel; oxidation; ASR
Series Title As a way of reducing the production costs of stacks by replacing ceramic components with metal components with a similar thermal expansion coefficient (TEC), today, much of the research work has focused on SOFCs operating at temperatures of under 800 degrees C. Some semi-commercial ferritic stainless steels (FSS) satisfy this TEC. Ikerlan has evaluated samples of two of these. Also, AMETEK stainless steel powders were tested in sintered disks until they were completely densified in order to compare results from dense and porous materials. The first tests performed by Ikerlan were conducted with dense samples and included the oxidation test in air at 800 degrees C and measurements of contact surface electrical resistance (area specific resistance, ASR), to compare electrochemical techniques (electrochemical impedance spectroscopy, EIS) with the traditional four-wire method and indirect measuring of the resistance through current and voltage measurements. An alloy from the last melt manufactured by the company ThyssenKrupp VDM GmbH performed best. These results did not differ greatly from the previous laboratory results attained during alloy development. Only AMETEK powder metallurgy materials were tested as porous bodies, to compare these with these dense materials. and were found to provide much higher oxidation levels, as might be expected. While dense materials can operate under the working conditions of the SOFC, porous materials still need new alloys. Series Volume
Serial Orig Record
no NU @ karnesky @ 497
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Athenes, M.; Soisson, F.; Bellon, P.; Martin, G. Solid State Diffusion and Configurational Kinetics Book Chapter 1999 Proceedings of the International Conference on Solid-Solid Phase Transformations 433-440 precipitation, ordering, nucleation, growth, coarsening, diffusion, vacancy, atomic scale, Monte Carlo simulation, kinetics no NU @ karnesky @ 277
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Blavette, D.; Martin, C.; Gallot, J. Atomic probe analysis of precipitates in an iron-chromium-nickel-aluminum (FeCr20Ni2Al2) alloy Journal Article 1982 Scr. Metall. 16, atom probe field ion microscopy no 8124
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Blavette, D.; Soisson, F.; Martin, G.; Pareige, C. Ordering and Phase Separation in Model Superalloys: 3D Atom Probe versus Monte Carlo simulation Book Chapter 1999 Proceedings of the International Conference on Solid-Solid Phase Transformations 65-72 ordering, phase separation, Ni-Al-Cr, 3D atom-probe, monte carlo simulation; 3D Atom Probe, Superalloys The kinetics of ordering and unmixing in model superalloys (NiCrAl) at 600C were effects in the ' investigated at the atomic scale using 3D atom probe and by transmission electron it ion here that microscopy. Very fine precipitates (lnm) with a well ordered structure (Ni3 Al) were observed in the early stages of growth At this stage, their composition was found very close to the equilibrium composition of the y' phase. Coarsening of y' precipitates was observed in the early stages, for particle radius under 2 nm Monte Carlo simulations of kinetics based on a atom-vacancy exchanges mechanism and using a residence time algorithm were also conducted. Experiments and simulations have shown a good agreement. Monte carlo simulations indicate that short range ordering of both Al and Cr precedes the nucleation and Ni3AI ordered phase. The Cr content in nuclei was foun: to be close to that of solution in the very early stages of phase separation no NU @ karnesky @ 275
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Brechet, Yves; Martin, Georges Nucleation problems in metallurgy of the solid state: recent developments and open questions Journal Article 2006 Comptes Rendus Physique 7 9-10 959-976 Coherent precipitation; Recrystallisation; Precipitation coherente; Recristallisation Nucleation processes play a key role in the microstructure evolution of metallic alloys during thermomechanical treatments. These processes can involve phase transformations (such as precipitation) and structural instabilities (such as recrystallisation). Although the word `nucleation' is used in both cases, the situation is profoundly different for precipitation and for recrystallisation on which this article is focussed. In the case of precipitation, species are conserved and the underlying physics is stochastic fluctuations, allowing the apparition of critical germs of the new phase. In the case of recrystallisation, the underlying physical phenomenon is the progressive growth of subgrain structures leading to an unstable configuration, allowing a dislocation free grain to grow at the expense of a dislocated one. The two cases require different types of modelling which are presented in the article. To cite this article: Y. Brechet, G. Martin, C. R. Physique 7 (2006). no NU @ karnesky @ 9593
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Cetronio, A.; Jones, J. P.; Martin, A. D. Computer simulation of ion images as an aid to indexing small crystallites Journal Article 1974 Surface Science Surf. Sci. 44 computer simulation; Field Ion Microscopy no 6715
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Clouet, E.; Nastar, M.; Barbu, A.; Sigli, C.; Martin, G. An Atomic and Mesoscopic Study of Precipitation Kinetics in Al-Zr-Sc Alloys Journal Article 2006 Advanced Engineering Materials 8 12 1228-1231 Aluminum alloys Kinetics Precipitation No abstract. 1527-2648 no NU @ karnesky @ E.Clouet2006 1856
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Clouet, Emmanuel; Barbu, Alain; La, Ludovic; Martin, Georges Precipitation kinetics of Al3Zr and Al3Sc in aluminum alloys modeled with cluster dynamics Journal Article 2005 Acta Materialia Acta Mater. 53 8 2313-2325 Precipitation; Kinetics; Aluminum alloys; Cluster dynamics Precipitation kinetics of Al3Zr and Al3Sc in aluminum supersaturated solid solutions is studied using cluster dynamics, a mesoscopic modeling technique which describes the various stages of homogeneous precipitation by a single set of rate equations. The only parameters needed are the interface free energy and the diffusion coefficient which are deduced from an atomic model previously developed to study the same alloys. A comparison with kinetic Monte-Carlo simulations based on the vacancy diffusion mechanism shows that cluster dynamics correctly predicts the precipitation kinetics provided a size dependent interface free energy is used. It also manages to reproduce reasonably well existing experimental data. no NU @ karnesky @ 211
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Clouet, Emmanuel; Nastar, Maylise; Barbu, Alain; Sigli, Cristophe; Martin, Geroges Precipitation in Al-Zr-Sc alloys:a comparison between kinetic Monte Carlo, cluster dynamics and classical nucleation theory Book Chapter 2005 Solid-Solid Phase Transformations in Inorganic Materials 2 683-703 Zr and Sc precipitate in aluminum alloys to form the Al3ZrxSc1−x compound which, for low supersaturations of the solid solution, exhibits the L12 structure. The aim of the present study is to model at an atomic scale the kinetics of precipitation and to build mesoscopic models so as to extend the range of supersaturations and annealing times that can be simulated up to values of practical interest. In this purpose, we use some ab initio calculations and experimental data to fit an Ising type model describing thermodynamics of the Al-Zr-Sc system. Kinetics of precipitation are studied with a kinetic Monte Carlo algorithm based on an atom-vacancy exchange mechanism. Cluster dynamics is then used to model at a mesoscopic scale all the different stages of homogeneous precipitation in the two binary Al-Zr and Al-Sc alloys. This technique correctly manages to reproduce both the kinetics of precipitation simulated with kinetic Monte Carlo as well as experimental observations. Focusing on the nucleation stage, it is shown that classical theory well applies as long as the short range order tendency of the system is considered. This allows us to propose an extension of classical nucleation theory for the ternary Al-Zr-Sc alloy. TMS Howe, J. M.; Laughlin, D. E.; Lee, J. K.; Dahmen, U.; Soffa, W. A. no NU @ karnesky @ 166
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D J Larson and D Lawrence and W Lefebvre and D Olson and T J Prosa and D A Reinhard and R M Ulfig and P H Clifton and J H Bunton and D Lenz and J D Olson and L Renaud and I Martin and T F Kelly Toward atom probe tomography of microelectronic devices Journal Article 2011 Journal of Physics: Conference Series 326 1 012030 Atom probe tomography and scanning transmission electron microscopy has been used to analyze a commercial microelectronics device prepared by depackaging and focused ion beam milling. Chemical and morphological data are presented from the source, drain and channel regions, and part of the gate oxide region of an Intel ® i5-650 p-FET device demonstrating feasibility in using these techniques to investigate commercial chips. 1742-6596 no NU @ karnesky @ 11288
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