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Oxidation of niobium particles embedded in a sintered ceramic matrix
Author(s) -
Tommaselli M. A. G.,
Mariano N. A.,
Pallone E. M. J. A.,
Kuri S. E.
Publication year - 2004
Publication title -
materials and corrosion
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.487
H-Index - 55
eISSN - 1521-4176
pISSN - 0947-5117
DOI - 10.1002/maco.200303767
Subject(s) - niobium , ceramic , materials science , ceramic matrix composite , thermogravimetric analysis , composite material , oxygen , composite number , matrix (chemical analysis) , diffusion , kinetics , metallurgy , chemical engineering , thermodynamics , chemistry , physics , organic chemistry , quantum mechanics , engineering
The toughness of ceramic materials can be improved through the inclusion of metallic particles in the ceramic matrix. The plastic deformation of the particles limits the rupture of the ceramic matrix. Al 2 O 3 ‐Nb composites show the ability of niobium to form a strong bond with Al 2 O 3 , but the poor resistance to oxidation of niobium hinders the use of niobium for high temperature applications. The study of the oxidation mechanism was done using thermogravimetric analysis under an oxygen atmosphere in order to obtain the oxidation reaction rate constants of the Al 2 O 3 ‐Nb composite. At the beginning the oxidation kinetics are linear, probably due to a great availability of oxygen. Later on, the oxidation mechanism showed to be parabolic, indicating that the process depends on the oxygen diffusion through the ceramic matrix.