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Role of Solute Segregation at Grain Boundaries During Final–Stage Sintering of Alumina
Author(s) -
JORGENSEN P. J.,
WESTBROOK J. H.
Publication year - 1964
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.1151-2916.1964.tb12996.x
Subject(s) - sintering , grain boundary , materials science , grain growth , grain boundary diffusion coefficient , grain boundary strengthening , non blocking i/o , diffusion , indentation hardness , grain size , metallurgy , mineralogy , microstructure , chemistry , thermodynamics , catalysis , biochemistry , physics
The addition of minor amounts of MgO or NiO to Al 2 O 3 inhibits grain growth during sintering and allows the sintering process to proceed to theoretical density by maintaining a high diffusion flux of vacancies from the pores to the grain boundaries. The inhibition of grain growth is accomplished by the segregation of solute at the grain boundaries, causing a decrease in the grain–boundary mobility. The segregation of MgO or NiO at the grain boundaries can be inferred from the results of the microhardness studies presented and is substantiated by autoradiographic experiments and also by lattice parameter determinations as a function of grain size.