Premium
Thermodynamic Analysis of Grain Aspect Ratio in Fibrous Microstructures of Silicon Nitride
Author(s) -
Raj Rishi,
Hoffmann Michael J.
Publication year - 1997
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.1151-2916.1997.tb03262.x
Subject(s) - aspect ratio (aeronautics) , silicon nitride , supersaturation , materials science , non equilibrium thermodynamics , anisotropy , kinetic energy , microstructure , silicon , nitride , thermodynamics , crystal (programming language) , composite material , metallurgy , optics , physics , classical mechanics , layer (electronics) , computer science , programming language
Needlelike, free‐floating ß‐crystals of silicon nitride, precipitated within a supersaturated Y‐Si‐Al‐O‐N oxynitride glass, apparently approach an equilibrium value of the aspect ratio. An expression that relates this aspect ratio to the anisotropy in the interfacial energies of the longitudinal and transverse interfaces of the crystal is derived. The prediction agrees reasonably well with theoretical estimates of the interfacial energies. Kinetic and stearic effects that often lead to nonequilibrium values of the aspect ratio are discussed.