ISSN:
1573-4870
Keywords:
Grain boundary composition
;
silicon nitride
;
lattice imaging
;
energy dispersive x-ray spectroscopy
;
analytical electron microscopy
Source:
Springer Online Journal Archives 1860-2000
Topics:
Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
Notes:
Abstract The chemical compositions of the grain boundary phases of silicon nitride (Si3N4) ceramics containing additives of 1 mole% and 10 mole% of an equi-molar mixture of Y2O3 and Nd2O3 have been studied by 300 kV field emission analytical electron microscopy. The energy dispersive x-ray spectra (EDS) are obtained from both two-grains and triple-grain junctions, where an electron beam of about 0.5 nm in diameter is focused. The thickness of the intergranular thin film is found to be about 1 nm, whose value is almost the same between two samples. The sintering additives are highly enriched at the triple-grain junctions, while they are less concentrated at the two-grain junctions. It is also shown that the additives are distributed inhomogeneously within the triple-grain junctions. Based on the composition analysis among the grain boundaries, an inhomogeneous grain boundary composition model for the Si3N4 ceramics is proposed.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1023/A:1022659412549
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