Download or read book ELABORATION ET CARACTERISATION MECANIQUE DES NANOCOMPOSITES ALUMINE CARBURE DE SILICIUM written by DAVID.. O'SULLIVAN and published by . This book was released on 1998 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'OBJECTIF DE CETTE ETUDE ETAIT DE DEVELOPPER UN PROTOCOLE DE FABRICATION DE NANOCOMPOSITES A MATRICE D'ALUMINE RENFORCEE PAR DES PARTICULES NANOMETRIQUES (

Download or read book ELABORATION ET CARACTERISATION DE CERAMIQUES D ALUMINE SOL GEL PURE ET DE NANOCOMPOSITES ALUMINE SOL GEL CARBURE DE SILICIUM written by NELSON HERIBERTO.. ALMEIDA CAMARGO and published by . This book was released on 1995 with total page 164 pages. Available in PDF, EPUB and Kindle. Book excerpt: UNE CERAMIQUE D'ALUMINE PURE A ETE ELABOREE PAR PROCEDE SOL-GEL EN UTILISANT UN PRECURSEUR ORGANO-MINERAL. LA FILIATION SOL--> GEL--> XEROGEL--> ALUMINE DE TRANSITION (CALCINATION A 900C)--> ALUMINE ALPHA (CALCINATION A T1> 1000C)--> CERAMIQUE (PRESSAGE SOUS CHARGE A T2 = 1550C) A FAIT L'OBJET D'UNE ANALYSE PHYSICO-CHIMIQUE ET MICROSTRUCTURALE EXHAUSTIVE. L'OPTIMISATION DE LA TEMPERATURE T1 A PERMIS D'OBTENIR UNE CERAMIQUE PRESENTANT UNE CONTRAINTE DE RUPTURE EN FLEXION PARTICULIEREMENT PERFORMANTE (ENVIRON 700 MPA). PUIS UNE POUDRE NANOMETRIQUE DE SIC (D = 20-30 NM) A ETE INCORPOREE (5% VOL.) AU SOL AVANT GELIFICATION, INCORPORATION CONDUISANT A UNE STABILISATION THERMIQUE DE L'ALUMINE DE TRANSITION. CE PHENOMENE A ETE EXPLIQUE SUR LA BASE D'UNE LIMITATION DES PROCESSUS DIFFUSIONNELS ASSOCIES A LA GERMINATION-CROISSANCE DE L'ALUMINE ALPHA, NECESSITANT AINSI UNE TEMPERATURE T1 SENSIBLEMENT PLUS ELEVEE POUR FORMER LE CORINDON. TENANT COMPTE DE CES OBSERVATIONS, DES ECHANTILLONS DE CERAMIQUE NANOCOMPOSITE ALUMINE/SIC ONT ETE PREPARES PAR PRESSAGE A CHAUD A DIFFERENTES TEMPERATURE T2 DE 1550C A 1750C. LES CARACTERISTIQUES MECANIQUES OBTENUES RESTENT TOUJOURS INFERIEURES A CELLE DE LA MATRICE D'ALUMINE PURE ET LA FRACTURE EST TRANSGRANULAIRE, CONSEQUENCE DE L'ETABLISSEMENT DE CONTRAINTES INTERNES ELEVEES AU COURS DU REFROIDISSEMENT DU MATERIAU. CES RESULTATS ONT ETE EXPLIQUES PAR L'ANALYSES DE LA MICRO- ET DE LA NANOSTRUCTURE DES MATERIAUX EN UTILISANT LES TECHNIQUES DE MICROSCOPIE ELECTRONIQUE. LES PROPRIETES ASSEZ MOYENNES OBTENUES, QUI RESULTENT EN PARTICULIER DE LA MAUVAISE DISPERSION DU RENFORT SIC DANS LA MATRICE, ONT PU ETRE SENSIBLEMENT AMELIOREES PAR UNE OPERATION D'ATTRITION DU XEROGEL COMPOSITE ASSOCIEE A UN RECUIT QUI LIMITE LES CONTRAINTES INTERNES. MAIS POUR OBTENIR DES CARACTERISTIQUES PERFORMANTES, DE NOMBREUX AUTRES PARAMETRES DOIVENT ETRE PRIS EN COMPTE. UNE ANALYSE DE CES PARAMETRES EST PRESENTEE

Download or read book laboration et propri t s m caniques de composites matrice d alumine renforc e par des trichites de carbure de silicium written by Frédéric Chambon and published by . This book was released on 1991 with total page 292 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Fabrication et caract risation de micro et nano composites alumine carbure de silicium pour des applications abrasives written by Christine Kermel and published by . This book was released on 2003 with total page 236 pages. Available in PDF, EPUB and Kindle. Book excerpt: Le but de ce travail était de rendre possible la production industrielle de grains abrasifs micro- et nanocomposites alumine-SiC aux propriétés supérieures à celles des abrasifs commerciaux en alumine. La synthèse hydrothermale (à partir de nitrate d'aluminium), suivie d'un pressage à chaud, a d'abord permis d'obtenir des nanocomposites Al2O3-SiC par voie aqueuse. Le produit intermédiaire de ce procédé est une poudre boehmite-SiC, qui présente une vitesse maximale de densification sans pression appliquée vers 1500°C. Or le boehmite est la matière première des grains abrasifs "alumine sol-gel" fabriqués industriellement, aussi avons nous choisi d'adapter ce procédé de fabrication par l'ajout d'une suspension de SiC avant l'étape de gélification. Les conditions de frittage naturel ont été étudiées en fonction de la taille et de la quantité de SiC ajouté. Les meilleures performance d'usure, otenues pour 1 vol. % SiC 200 nm (1500 °C) et 1 vol. % de SiC 14μm (1400 °C), sont supérieures à celles des abrasifs commerciaux en alumine. Pour de bonnes propriétés d'usure, les grains abrasifs doivent avoir une densité apparente ≥ 95 %, une dureté ≥ 20 GPa, et une matrice à grains fins (1 à 2μm)

Download or read book Elaboration microstructure et propri t s m caniques d alliages d aluminium renforc s par des particules de SiC written by and published by . This book was released on 1993 with total page 153 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ce projet de recherche porte sur la fabrication et la caractérisation de la microstructure et des propriétés mécaniques de composites SiC/alliage 6061'. Après avoir fabriqué des billettes composites contenant 15 p.cent de carbure de silicium, on a utilisé 2 granulométries différentes des carbures de silicium. Par la suite, on a effectué des essais de traction et Charpy à différentes températures, des essais de ténacité, des mesures de porosité ainsi qu'une étude de maturation du composite. Le projet se divise en 3 parties: élaboration du composite, étude de la maturation du composite, étude de la maturation du composite à différentes températures, et la comparaison des propriétés mécaniques obtenues.

Download or read book ICREEC 2019 written by Ahmed Belasri and published by Springer Nature. This book was released on 2020-06-10 with total page 659 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book highlights peer reviewed articles from the 1st International Conference on Renewable Energy and Energy Conversion, ICREEC 2019, held at Oran in Algeria. It presents recent advances, brings together researchers and professionals in the area and presents a platform to exchange ideas and establish opportunities for a sustainable future. Topics covered in this proceedings, but not limited to, are photovoltaic systems, bioenergy, laser and plasma technology, fluid and flow for energy, software for energy and impact of energy on the environment.

Download or read book Flexoelectricity in Liquid Crystals written by Agnes Buka and published by World Scientific. This book was released on 2013 with total page 299 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book intends to give a state-of-the-art overview of flexoelectricity, a linear physical coupling between mechanical (orientational) deformations and electric polarization, which is specific to systems with orientational order, such as liquid crystals. Chapters written by experts in the field shed light on theoretical as well as experimental aspects of research carried out since the discovery of flexoelectricity. Besides a common macroscopic (continuum) description the microscopic theory of flexoelectricity is also addressed. Electro-optic effects due to or modified by flexoelectricity as well as various (direct and indirect) measurement methods are discussed. Special emphasis is given to the role of flexoelectricity in pattern-forming instabilities. While the main focus of the book lies in flexoelectricity in nematic liquid crystals, peculiarities of other mesophases (bent-core systems, cholesterics, and smectics) are also reviewed. Flexoelectricity has relevance to biological (living) systems and can also offer possibilities for technical applications. The basics of these two interdisciplinary fields are also summarized.

Download or read book HIE ISOLDE the Technical Options written by European Organization for Nuclear Research and published by . This book was released on 2006 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Nonlinear Optical Materials written by Jerome V. Moloney and published by Springer Science & Business Media. This book was released on 1998-08-13 with total page 270 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mathematical methods play a significant role in the rapidly growing field of nonlinear optical materials. This volume discusses a number of successful or promising contributions. The overall theme of this volume is twofold: (1) the challenges faced in computing and optimizing nonlinear optical material properties; and (2) the exploitation of these properties in important areas of application. These include the design of optical amplifiers and lasers, as well as novel optical switches. Research topics in this volume include how to exploit the magnetooptic effect, how to work with the nonlinear optical response of materials, how to predict laser-induced breakdown in efficient optical devices, and how to handle electron cloud distortion in femtosecond processes.

Download or read book Physical Properties of Amorphous Materials written by David Adler and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 448 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Institute for Amorphous Studies was founded in 1982 as the international center for the investigation of amorphous mate rials. It has since played an important role in promoting the und er standing of disordered matter in general. An Institute lecture series on "Fundamentals of Amorphous Materials and Devices" was held during 1982-83 with distinguished speakers from universities and industry. These events were free and open to the public ,and were attended by many representatives of the scientific community. The lectures themselves were highly successful inasmuch as they provided not only formal instruction but also an opportunity for vigorous and stimulating debate. That last element could not be captured within the pages of a book I but the lectures concentrated on the latest advances in the field I which is why their essential contents are he re reproduced in collective form. Together they constitute an interdisciplinary status report of the field. The speakers brought many different viewpoints and a variety of back ground experiences io bear on the problems involved I but though language and conventions vary I the essential unity of the concerns is very clear I as indeed are the ultimate benefits of the many-sided approach.

Download or read book Forest Fire Research written by Universidade de Coimbra and published by . This book was released on 2010 with total page 355 pages. Available in PDF, EPUB and Kindle. Book excerpt: