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Morphological Changes of an Intergranular Thin Film in a Poly crystalline Spinel
Author(s) -
LANGE F. F.,
CLARKE D. R.
Publication year - 1982
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.1151-2916.1982.tb10341.x
Subject(s) - intergranular corrosion , spinel , materials science , phase (matter) , instability , diffusion , rayleigh–taylor instability , enhanced data rates for gsm evolution , aluminium , composite material , mineralogy , metallurgy , microstructure , geology , chemistry , thermodynamics , mechanics , physics , telecommunications , organic chemistry , computer science
An intergranular second phase, present as a film in a large‐grained MgAl 2 O 4 densified with LiF, was observed, on sequential heat treatment at 1500° C, to progressively reduce its area by first forming slender fingers which then break up into spheroid‐shaped islands. This “beading” process is an example of a Rayleigh instability driven by capillarity processes. Electron microscopy revealed that the islands consist of two phases (presumably LiF and MgAl 2 O 4 ), characteristic of a solidified melt. The observed morphologies are more than likely characteristic of many intergranular phases which form nonzero contact angles with the major phase. An analysis is presented showing that perturbations on the edge of a receding plate can grow by surface diffusion.