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Electron Microscopy Study of the Effect of Iron in Reaction‐Sintered Silicoa Nitride
Author(s) -
SHINOZAKP S.,
MILBERG M. E.
Publication year - 1981
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.1151-2916.1981.tb09874.x
Subject(s) - silicide , materials science , microstructure , transmission electron microscopy , grain boundary , silicon nitride , scanning electron microscope , metallurgy , grain size , silicon , mineralogy , crystallography , composite material , nanotechnology , chemistry
The microstructure, crystal structure, and chemical composition of reaction‐sintered Si 3 N 4 containing iron were studied using conventional and scanning transmission electron microscopy. It was found that the grains of β ‐Si 3 N 4 were large and blocklike with well‐developed facets, a series of voids along some grain boundaries, a subgrain of iron silicide near the periphery, and penetration of iron silicide into the three‐grain junctions and grain boundaries. At some distance from each β ‐Si 3 N 4 grain was a region of small α‐Si 3 N 4 grains, with no evidence of iron silicide. Between this region and the β ‐Si 3 N 4 grain was a zone containing both α‐ and β ‐Si 3 N 4 and iron silicide. These observations suggest that the large β ‐Si 3 N 4 grains grow in liquid iron silicide, that the smaller α‐Si 3 N 4 grains grow from the vapor, and that the latter are converted to the β form by solution in, and reprecipitation from, liquid iron silicide.