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Compression Creep of Alumina Containing Interfacial Silicon, Carbon, and Nitrogen, Derived from a Polysilazane Precursor
Author(s) -
Castellan Enzo,
Shah Sandeep R.,
Raj Rishi
Publication year - 2010
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.1551-2916.2009.03515.x
Subject(s) - creep , materials science , composite material , pyrolysis , carbon fibers , silicon carbide , nanocomposite , silicon , nitrogen , stress (linguistics) , diffusion creep , grain boundary , composite number , chemical engineering , metallurgy , microstructure , chemistry , linguistics , philosophy , organic chemistry , engineering
Silicon, carbon, and nitrogen were introduced into alumina polycrystals by in situ pyrolysis of a polysilazane precursor. These specimens were tested in compression creep from 1300° to 1400°C at stresses ranging from 60 to 120 MPa. The creep rates were comparable with those obtained by Thompson and colleagues. in nanocomposites, which had been fabricated by the powder route from alumina and silicon carbide. The convergence of these two data sets suggests that the retardation of creep rate in these composites is likely due to a chemical alteration of the grain boundaries in alumina, which either retards interfacial diffusion or creates an interface reaction barrier to diffusional creep, or both. A threshold stress and the absence of primary creep are unusual manifestations of the present experiments.