Tuning of the high temperature behaviour of Si–C–N ceramics via the chemical crosslinking of poly(vinylmethyl-co-methyl)silazanes with controlled borane contents

Open Ceramics

David Lopez-Ferber¹  Diane Fonblanc²  Samuel Bernard³  Georges Chollon⁴  Antoine Viard⁴  Marion Schmidt⁴  Pierre Carles⁴  Mélanie Wynn⁴  Fabrice Rossignol⁴  Christel Gervais⁵ 

[1] Corresponding author.;BJS Ceramics GmbH, Siemensstraße 6a L, D-86368, Gersthofen L, Germany;Sorbonne Université, CNRS, Laboratoire de Chimie de La Matière Condensée de Paris, LCMCP, UMR 7574, F-75005, Paris, France;Univ. Limoges, CNRS, IRCER, UMR 7315, F-87000, Limoges, France;University of Bordeaux, Laboratoire des Composites ThermoStructuraux (LCTS), UMR 5801: CNRS-Herakles(Safran)-CEA-UBx 3, Allée de La Boétie, 33600, Pessac, France;

关键词: Si–B–C–N;    Polysilazanes;    Boron;    Polymer derived ceramics;    Crystallization;   

DOI  :  

来源: DOAJ

【 摘 要 】

The thermal stability, elemental/phase composition evolution and crystallization behaviour of Si–B–C–N ceramics obtained by the pyrolysis of a series of poly (vinylmethyl-co-methyl)silazanes displaying various boron contents were investigated through annealing in the temperature range 1000–1800 ​°C under nitrogen atmosphere. The increase of the boron content in the early stage of the process involved the nucleation of β-SiC, inhibited the crystallization of α-Si3N4 and modified the activity of the sp2-hybridised carbon phase in the derived ceramics obtained at 1000 and 1400 ​°C. At 1800 °C, low boron content Si–B–C–N ceramics gradually evolved toward a major SiC phase mainly formed via the carbothermal reaction of amorphous Si3N4 whereas high boron content Si–B–C–N ceramics led to highly stable materials with a complex microstructure made of SiC, Si3N4 and a BN-rich B(C)N phase that inhibited the activity of sp2-hybridised carbon toward the carbothermal reaction of amorphous Si3N4 and significantly reduced the SiC crystallization process.

【 授权许可】

Unknown