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Sintering Analysis of a Fine‐Grained Alumina–Magnesia Spinel Powder
Author(s) -
Benameur Nassira,
BernardGranger Guillaume,
Addad Ahmed,
Raffy Stéphane,
Guizard Christian
Publication year - 2011
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.1551-2916.2010.04271.x
Subject(s) - spinel , sintering , materials science , grain boundary , grain growth , grain boundary diffusion coefficient , diffusion , isothermal process , metallurgy , grain size , magnesium , mineralogy , activation energy , microstructure , thermodynamics , chemistry , physics
Pressureless sintering in air of a fine‐grained alumina–magnesia spinel (MgAl 2 O 4 ) powder has been investigated using anisothermal and isothermal methods. Grain growth is controlled by the grain boundaries and densification is controlled by volume diffusion or grain‐boundary diffusion (no possibility to do a distinction). The apparent activation energies measured for grain growth and densification are 1100±50 and 915±50 kJ/mol, respectively. Grain boundaries and triple points have a different composition than the core of spinel grains. This could be the reason for the exceptionally high values of activation energies measured for grain growth and densification.