{"record":{"leader":"cx  r22     2  45","datafield":[{"ind2":" ","ind1":" ","subfield":{"code":"a","content":"20171021afrey50      ba0"},"tag":100},{"ind2":" ","ind1":" ","subfield":[{"code":"a","content":"fre"},{"code":2,"content":"639-2"}],"tag":101},{"ind2":" ","ind1":" ","subfield":{"code":"a","content":2003},"tag":103},{"ind2":" ","ind1":" ","subfield":[{"code":"a","content":"k"},{"code":"f","content":"fre"}],"tag":104},{"ind2":" ","ind1":" ","subfield":[{"code":"a","content":0},{"code":"b","content":"#"},{"code":"c","content":"#"}],"tag":106},{"ind2":" ","ind1":" ","subfield":{"code":"a","content":"AFNOR"},"tag":152},{"ind2":" ","ind1":" ","subfield":{"code":"a","content":"Oeuvre Textuelle"},"tag":189},{"ind2":" ","ind1":" ","subfield":[{"code":7,"content":"ba0yba0"},{"code":"t","content":"Elaboration et caractérisation d'une protection anti-oxydation pour matériaux carbonnes, le système HfB(2)-SiC"}],"tag":241},{"ind2":" ","ind1":" ","subfield":[{"code":7,"content":"ba0yba0y"},{"code":"a","content":"L\u2019objectif de ce travail a été la réalisation et la caractérisation d\u2019une protection contre l\u2019oxydation de matériaux carbonés, constituée d\u2019une couche composite HfB2SiC et d\u2019une couche d\u2019accrochage de SiC. Le procédé d\u2019élaboration utilise l\u2019infiltration de silicium liquide dans une préforme poreuse constituée de grains de HfB2 et de carbone issu de la décomposition d\u2019une résine. La réaction entre le silicium et le carbone forme une matrice de SiC et à l\u2019interface le silicium réagit avec le substrat pour donner SiC et assurer un accrochage chimique et mécanique. Les conditions d\u2019élaboration ont été étudiées afin de réaliser un revêtement compact et homogène. La microstructure obtenue se compose de grains de HfB2 et de nanoparticules de SiC mise en évidence par microscopie électronique en transmission. Une phase intermédiaire contenant Hf-B-Si-C a été détectée, par spectrométrie Auger, en périphérie des grains de HfB2. Le comportement à l\u2019oxydation a été étudié dans un large domaine de pression d\u2019oxygène (1-200 mbar) en montée linéaire de température et en régime isotherme. deux domaines correspondant respectivement à l\u2019oxydation de la phase intermédiaire vers 600°C-700°C et des nanoparticules de SiC vers 900-1000°C, conduisent à la formation d\u2019un verre borosilicaté cicatrisant. La présence de B2O3 à haute température favorise la dissolution de HfO2 dans le verre. La phase vitreuse stable à très haute température constitue alors une barrière de diffusion à l\u2019oxygène de quelques dizaines de microns. En régime isotherme, la cinétique tend rapidement vers un régime parabolique très lent jusqu\u2019à 1700°C. A basse pression partielle d\u2019oxygène un domaine d\u2019oxydation active apparaît. La comparaison avec le carbure de silicium montre que le verre formé est plus stable que la silice pure"}],"tag":300},{"ind2":" ","ind1":" ","subfield":[{"code":7,"content":"ba0yba0y"},{"code":"a","content":"The aim of this work is the elaboration and the caracterisation of HfB2SiC oxidation protection coating for carbon based materials. Silicon carbide is formed by reactive infiltration of silicon through a porous carbon/HfB2 grains layer. The coating microstructure is composed of HfB2 grains surrounded by SiC nanoparticles and a phase containing Hf-B-Si-C at the interface between HfB2 and Sic. The oxidation behaviour was studied between 1 and 200 mbar by linear increase of temperature and under isothermal conditions. A sealing refractory glass, more stable than pure silica, is formed. The oxidation kinetic follows very quickly a slow parabolic law up to 1 700°C"}],"tag":300},{"ind2":0,"ind1":" ","subfield":[{"code":"b","content":"Thèse doctorat"},{"code":"c","content":"Science des matériaux céramiques et traitements de surface"},{"code":"e","content":"Limoges"},{"code":"d","content":2003}],"tag":328},{"ind2":" ","ind1":" ","subfield":[{"code":7,"content":"ba0yba0"},{"code":"t","content":"Elaboration and caracterization of an anti-oxidation protection coating for carbon based materials, HfB(2)-SiC system"}],"tag":441},{"ind2":1,"ind1":" ","subfield":[{"code":3,"content":"076323277"},{"code":7,"content":"ba0yba07"},{"code":"a","content":"Richet"},{"code":"b","content":"Nicolas"},{"code":"f","content":"1976-...."},{"code":4,"content":"070"}],"tag":501},{"ind2":1,"ind1":" ","subfield":[{"code":3,"content":"071410899"},{"code":7,"content":"ba0yba07"},{"code":"a","content":"Goursat"},{"code":"b","content":"Paul"},{"code":"f","content":"1942-...."},{"code":4,"content":727}],"tag":501},{"ind2":2,"ind1":0,"subfield":[{"code":3,"content":"059358041"},{"code":7,"content":"ba0yba07"},{"code":"a","content":"Université de Limoges"},{"code":"b","content":"Faculté des sciences et techniques"},{"code":4,"content":985}],"tag":511},{"ind2":2,"ind1":0,"subfield":[{"code":3,"content":"026403315"},{"code":7,"content":"ba0yba07"},{"code":"a","content":"Université de Limoges"},{"code":"c","content":"1968-...."},{"code":4,"content":295}],"tag":511},{"ind2":" ","ind1":" ","subfield":[{"code":3,"content":"031401295"},{"code":"a","content":"Matériaux organiques"},{"code":3,"content":"027360067"},{"code":"x","content":"Oxydation"},{"code":2,"content":"rameau"}],"tag":606},{"ind2":" ","ind1":" ","subfield":[{"code":3,"content":"056562411"},{"code":"a","content":"Revêtement de surface"},{"code":2,"content":"rameau"}],"tag":606},{"ind2":" ","ind1":" ","subfield":[{"code":3,"content":"03154777X"},{"code":"a","content":"Carbure de silicium"},{"code":2,"content":"rameau"}],"tag":606},{"ind2":" ","ind1":" ","subfield":[{"code":7,"content":"ba0yba0"},{"code":3,"content":"027253139"},{"code":"a","content":"Thèses et écrits académiques"},{"code":2,"content":"rameau"}],"tag":608},{"ind2":" ","ind1":0,"subfield":{"code":"a","content":"Protection anti-oxydation"},"tag":610},{"ind2":" ","ind1":0,"subfield":{"code":"a","content":"Diborure d'Hafnium"},"tag":610},{"ind2":" ","ind1":0,"subfield":{"code":"a","content":"Infiltration reactive"},"tag":610},{"ind2":" ","ind1":" ","subfield":[{"code":"a","content":530},{"code":2,"content":"TEF"}],"tag":686},{"ind2":3,"ind1":" ","subfield":[{"code":"a","content":"FR"},{"code":"b","content":"Abes"},{"code":"c","content":20250930},{"code":"g","content":"AFNOR"}],"tag":801}],"controlfield":[{"tag":"001","content":212767747},{"tag":"003","content":"http://www.idref.fr/212767747"},{"tag":"004","content":20171021},{"tag":"005","content":20250930013344},{"tag":"006","content":"0499"},{"tag":"007","content":"0499"},{"tag":"008","content":"Tr2"}]}}