Morniroli J.P.,Ecole Nationale Superieure de Chimie de Lille |
Ji G.,CNRS Materials and Transformations Unit of UMET |
Jacob D.,CNRS Materials and Transformations Unit of UMET
Ultramicroscopy | Year: 2012
This systematic method allows the unambiguous identification of the extinction and diffraction symbols of a crystal by comparison of a few experimental Precession Electron Diffraction (PED) patterns with theoretical patterns drawn for all the extinction and diffraction symbols. The method requires the detection of the Laue class, of the kinematically forbidden reflections and of the shift and periodicity differences between the reflections located in the First-Order Laue Zone (FOLZ) with respect to the ones located in the Zero-Order Laue Zone (ZOLZ). The actual space group can be selected, among the possible space groups connected with each extinction symbol or diffraction symbol, from the identification of the point group. This point group is available from observation of the 2D symmetry of the ZOLZ on Convergent-Beam Electron Diffraction (CBED) patterns. © 2012 Elsevier B.V.
Becquart C.S.,Ecole Nationale Superieure de Chimie de Lille |
Becquart C.S.,Electricite de France |
Domain C.,Electricite de France
Metallurgical and Materials Transactions A: Physical Metallurgy and Materials Science | Year: 2011
This article gives an overview of the strategy followed nowadays to model the evolution of metallic alloy microstructures under irradiation. For this purpose, multiscale approaches are very often used, which rely on modeling techniques appropriate to each time and space scale. The main methods used are ab-initio calculations, classical molecular dynamics (MD), kinetic Monte Carlo (KMC), mean field rate theory (MFRT), and dislocation dynamics (DD). These methods are briefly presented along with some of their typical uses and main drawbacks. Some examples are provided of the typical information obtained with each of the techniques. © 2010 The Minerals, Metals & Materials Society and ASM International.
Ji G.,CNRS Materials and Transformations Unit of UMET |
Morniroli J.-P.,Ecole Nationale Superieure de Chimie de Lille
Journal of Applied Crystallography | Year: 2013
The space group of a new metastable orthorhombic Al2Cu phase, located in the Al-rich interfacial region of an Al-Cu friction stir weld, was unambiguously identified as Ic2m by a recently developed systematic method combining precession electron diffraction and convergent-beam electron diffraction. This metastable phase has the same tetragonal lattice as its stable θ-Al2Cu counterpart (tetragonal, I4/mcm, No. 140). The tetragonal-to-orthorhombic symmetry lowering is due to slight modifications of the atomic positions in the unit cell. This metastable phase can be transformed into the stable θ-Al2Cu phase by in situ irradiation within the transmission electron microscope. Copyright © International Union of Crystallography 2013.
Agency: Cordis | Branch: FP7 | Program: CP-TP | Phase: NMP.2012.2.2-5 | Award Amount: 6.98M | Year: 2013
Electrical and electronic (EE) applications including housings, wire and cable, and internals such as connectors are the largest market for flame retardants (FR) in plastics globally. The need for flame retardancy is increasing due to electronics miniaturization and higher temperatures in both processing and use. PHOENIX project is an ambitious multidisciplinary innovative threefold approach to develop: (i) A new concept of FR nanostructured materials, based on new non-halogenated flame-retardants applying nanotechnology to replace hazardous chemicals to produce sustainable FR additives based on nanolayered structures and modified lignins, produced with innovative and green chemical routes, for thermoplastic and thermoset applications. (ii) Innovative processing routes, providing solutions to the demands of the EU Industry regarding FR, finding a true cost-effective and sustainable alternative to existing non-environmentally friendly HFR, which allows simultaneously a significant improvement of mechanical properties and processability, highly limited with the existing non-halogenated FR available in the market for compounding, extrusion and injection moulding processes. New compounding techniques such as Nanodirekt process, and high innovative systems, such as ultrasounds mixing systems coupled to extrusion and injection equipments, will assure high nanoparticles dispersion in the polymer nanocomposites and in the final pieces, thus achieving optimal properties. (iii) Simulation and modelling of compounding processes for the preparation of optimal nanocomposites, avoiding aggregates and achieving the best dispersion of the nanoparticles in the polymer matrix. The achievement of these results will represent a significant advantage to the participating SMEs and in turn to the End-Users demanding high-performance environmentally friendly FR materials to manufacture high-performance parts.
Agency: Cordis | Branch: FP7 | Program: JTI-CS | Phase: JTI-CS-2012-1-SGO-02-041 | Award Amount: 549.93K | Year: 2013
[Analysis] The problem of finding a fluid for two phase capillary pumped cooling systems is a multiobjective one, considering the numerous properties to match. Besides we can expect to find a fluid within the tens of thousands of existing molecules, which have not been tested for this application, or a fluid that could be easily synthesised from an existing fluid. The critical point is finding the fluid among databases and/ or identifying chemical functions that would enable an existing fluid to match the specifications. Finally we can expect mixtures to be suitable as much as pure fluids. [Strategy] Rather than undertaking an inefficient trial and error search, we propose to implement a computer aided molecule and mixture design approach based on reverse engineering. Such a strategy combines bottom-up and top-down approaches to find fluids that can match a large set of specification together. [Workpackages] The first task (WP1) consists in building a mathematical performance function encompassing all the property specifications and screen potentially interesting chemical families. Second, a systematic computer based search is run to issue a list of candidate fluids (WP2). It combines two existing computer tools from the partners: a bottom-up approach to account for feasible chemical synthesis pathways, and top-down search based on group contribution property estimation methods to explore new pure compounds and mixtures. Third, the candidate list is narrowed by refining property calculations by using accurate first principle methods (WP3). They will also provide an electronic signature of the ideal fluid. The fourth task concerns the fluid choice and is possible synthesis (WP4). Fifth, experimental measurements are performed to validate a few candidates (WP5).