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Particle‐Inhibited Grain Growth in AI 2 O 3 ‐SiC: I, Experimental Results
Author(s) -
Stearns Laura C.,
Harmer Martin P.
Publication year - 1996
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.1151-2916.1996.tb08071.x
Subject(s) - grain growth , volume fraction , annealing (glass) , materials science , grain size , grain boundary , microstructure , particle size , analytical chemistry (journal) , metallurgy , mineralogy , crystallography , composite material , chemistry , chromatography
An extensive experimental study has been conducted to examine the influence of ultraflne SiC particles on grain growth in A1 2 O 3 . Grain growth has been studied as a function of annealing time, particle volume fraction, and annealing temperature. The SiC particles reduce the grain‐growth rate of A1 2 O 3 by >3 orders of magnitude, resulting in final grain sizes that decrease with increasing particle volume fraction. The fraction of SiC particles on grain boundaries, φ, has been measured as a function of annealing time, particle volume fraction, and annealing temperature. φ decreases during grain‐growth anneals, implying that grain boundaries are able to break free from particles and this is true to a greater extent for smaller volume fractions of particles. Further, it has been discovered that φ and average grain size, G , are strongly correlated, such that any increase in G results in a predictable decrease in pH. This new finding has revealed a path for microstructure development in this system that proves to be critical in the equilibrium and kinetic analyses described in a companion paper.