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Effect of Ammonia Treatment on the Crystallization of Amorphous Silicon–Carbon–Nitrogen Ceramics Derived from Polymer Precursor Pyrolysis
Author(s) -
Wan Julin,
Gasch Matthew J.,
Mukherjee Amiya K.
Publication year - 2002
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.1151-2916.2002.tb00132.x
Subject(s) - pyrolysis , crystallization , ceramic , materials science , chemical engineering , polymer , ammonia , amorphous solid , nitrogen , carbon fibers , composite material , composite number , chemistry , organic chemistry , engineering
An effort was made toward modifying the Si 3 N 4 ‐SiC phase ratio in bulk nanocomposites obtained from polymer precursors. While pyrolyzing the polymer, flowing ammonia was introduced, to facilitate a chemical exchange, resulting in a different C/N ratio in the ceramic pyrolysis product. A pre‐pyrolysis/binding/pyrolysis approach was used for sample consolidation. Comparison was made between the crystallization behavior of the pyrolysis‐derived ceramic powders and consolidated bulk samples. A profound enhancement in crystallization tendency was observed in the consolidated samples whose nitrogen content was increased by ammonia treatment. A mechanism based on the particle/binder interface energy was proposed to account for this observation.