5 research outputs found

    Reuters Institute Digital News Report 2023

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    Le ‘Reuters Institute’ (University of Oxford) annonce la mise en ligne de son rapport « Digital News Report 2023 » sur la consommation d’informations numĂ©riques auprĂšs de plus de 93 000 consommateurs d’informations en ligne sur 46 pays

    Reuters Institute Digital News Report 2022

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    Cette Ă©tude consacrĂ©e au journalisme a Ă©tĂ© commandĂ©e par l’Institut Reuters pour comprendre comment les "news" alimentent un certain nombre de pays. La recherche a Ă©tĂ© menĂ©e par YouGov en utilisant un questionnaire en ligne de fin janvier Ă  dĂ©but fĂ©vrier 2022

    Coatings by thermal spray

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    Thermal spray is a technology that allows the development of large parts, which cannot be produced by powder metallurgy for technical and economical reasons, with hardmetal characteristics via the application of thick hardmetal coatings. Thermally sprayed hardmetal coatings are predominantly mechanically bonded to the substrate having a typical thickness within the range 100-500 ÎŒm. This chapter reviews different spray processes, with focus on the currently most important high-velocity oxy-fuel and high-velocity air fuel processes, and the properties of the different feedstock powders in a historical context. The properties of the most important hard phases, namely, WC and Cr3C2 and TiC as an alternative, are discussed. Commercially available hardmetal compositions are reviewed. Since the spray process influences the chemical and phase compositions, coating formation and microstructures are discussed. The most important methods of coating characterization, such as microstructural analysis; X-ray diffraction for the study of phase composition; measurements of hardness, Young's modulus and indentation fracture; and thermophysical properties are presented. Corrosion properties, the influence of heat treatments on coating microstructure and the oxidation in service are reviewed. Wear protection (abrasion, erosion and sliding wear resistance) and potential new applications are also discussed
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