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Enhanced Creep Resistant Silicon‐Nitride‐Based Nanocomposite
Author(s) -
Dusza J.,
Kovalčík J.,
Hvizdoš P.,
Šajgalík P.,
Hnatko M.,
Reece M. J.
Publication year - 2005
Publication title -
journal of the american ceramic society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.9
H-Index - 196
eISSN - 1551-2916
pISSN - 0002-7820
DOI - 10.1111/j.1551-2916.2005.00289.x
Subject(s) - materials science , creep , silicon nitride , sintering , microstructure , composite material , nanocomposite , silicon carbide , grain boundary , grain size , nitride , stress (linguistics) , silicon , carbide , pyrolytic carbon , metallurgy , chemical engineering , pyrolysis , linguistics , philosophy , layer (electronics) , engineering
Silicon nitride–silicon carbide nanocomposite has been prepared by an in situ method that utilizes C+SiO 2 carbo‐thermal reduction during the sintering process. The developed material is nearly defect free and consists of a silicon nitride matrix with an average grain size of approximately 200 nm with inter‐ and intra‐granular SiC particles with sizes of approximately 150 and 40 nm, respectively. The creep behavior was investigated in bending at temperatures from 1200° to 1450°C, under stresses ranking from 50 to 150 MPa in air. The stress exponents are in the interval from 0.8 to 1.28 and the apparent activation energy is 480 kJ/mol. A significantly enhanced creep resistance was achieved by the incorporation of SiC nanoparticles into the matrix. This is because of a change of the microstructure and grain boundary chemistry leading to a change of creep mechanism and creep rate.