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Microstructure of a Ce 0.1 Zr 0.9 O 2 – MgAl 2 O 4 Ceramic Matrix Composite for Use in Dentistry
Author(s) -
Krumeich Frank,
Wörle Micheal,
Nesper Reinhard,
Höland Marlies,
Ritzberger Christian,
Rothbrust Frank,
Chevalier Jerome,
Rheinberger Volker M.,
Höland Wolfram
Publication year - 2014
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/jace.12800
Subject(s) - microstructure , materials science , monoclinic crystal system , tetragonal crystal system , rietveld refinement , phase (matter) , crystallography , transmission electron microscopy , analytical chemistry (journal) , mineralogy , crystal structure , composite material , chemistry , nanotechnology , organic chemistry , chromatography
A ceramic matrix composite ( CMC ) with the chemical composition of 90 wt% Ce 0.1 Zr 0.9 O 2 and 10 wt% MgAl 2 O 4 was produced by filter‐pressing, drying, and heat treatment at 1400°C. The internal microstructure was studied using the transmission electron microscopy ( TEM ) technique combined with energy‐dispersive X ‐ray spectroscopy. Because of the intended use in dentistry, the surfaces of the as‐fired and of the mechanically treated samples were characterized by atomic force microscopy ( AFM ) and X ‐ray diffraction ( XRD Rietveld analysis). This study revealed that Ce 0.1 Zr 0.9 O 2 and MgAl 2 O 4 spinel are the only crystalline phases present in the CMC material. Nevertheless, apart from the tetragonal Ce 0.1 Zr 0.9 O 2 , its monoclinic phase was identified as a third crystal phase in the as‐fired sample with an amount of ~2.5 wt%, at the surface of polished (5.3 wt%) and roughened (8 wt%) specimens. In sum, the microstructure of the CMC material is homogeneous and can be modified by mechanical surface treatment leading to a partial transformation of the tetragonal phase of the Ce 0.1 Zr 0.9 O 2 component into the monoclinic one. This partial transformation is also visible in AFM , with occurrence of transformation bands. The mechanism yield in surface compressive stress can be determined according to the Williamson and Hall method. The authors conclude that the absence of microcrack formation during polishing or roughening confirms the high flaw tolerance of such a CMC material.