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Statistical Analysis of the Intergranular Film Thickness in Silicon Nitride Ceramics
Author(s) -
Kleebe HansJoachim,
Cinibulk Michael K.,
Can Rowland M.,
Rüble Manfred
Publication year - 1993
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.1151-2916.1993.tb08319.x
Subject(s) - grain boundary , materials science , amorphous solid , ceramic , silicon nitride , intergranular corrosion , composite material , silicon , mineralogy , microstructure , crystallography , metallurgy , chemistry
Silicon nitride materials typically reveal thin amorphous intergranular films along grain boundaries, with only the exception of special boundaries. It is known that such grainboundary films strongly affect the high‐temperature properties of the bulk material. High‐resolution electron microscopy (HREM) was used to study these amorphous films in different Si 3 N 4 ceramics. The observed film thicknesses at grain boundaries in these materials varied between 5and 15 Å. It was shown that the grain‐boundary film thickness strongly depends on film chemistry. Careful inspections of film‐thickness measurements across grain boundaries in a given material suggest that the film widths vary on the order of 1 Å. Therefore, a quantitative evaluation should allow for the determination of the standard deviation of the film thickness. The amorphous film widths along grain boundaries in four materials were measured over the entire length (up to 1 μm) of the grain boundary between two triple points. Forty to fifty data points were evaluated for each boundary, giving a Gaussian‐like distribution of the film thickness around a median value, which corresponded well with the film width measured from single HREM micrographs. The accuracy achieved by the statistical method was better than ± 1 Å.