Cavity Evolution During Tensile Creep of Si3N4

Autor: Sheldon M. Wiederhorn, William Luecke, Gabrielle G. Long, Bernard J. Hockey
Rok vydání: 1992
Předmět:
Zdroj: MRS Proceedings. 287
ISSN: 1946-4274
0272-9172
Popis: We have characterized the evolution of cavities during tensile creep of a Y2O3-hot isostatically pressed Si3N4, using precision density measurements, small-angle x-ray scattering (SAXS) and transmission electron microscopy (TEM). The cavities are bimodally distributed in size. Lenticular, 200 nm-size cavities are common, and lie primarily on two-grain boundaries. Irregularly shaped 500-1000 nm-size cavities are rare and lie at multi-grain junctions, but comprise approximately half of the total volume fraction of cavities. Although the material shows a continuous decrease in strain rate with strain, the cavity volume fraction evolves linearly with strain. Cavities account for approximately 85% of the total strain at any point during creep.
Databáze: OpenAIRE
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