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Deformation behavior of nanocrystalline titania particles accessed by complementary in situ electron microscopy techniques
Author(s) -
Herre Patrick,
Romeis Stefan,
Mačković Mirza,
Przybilla Thomas,
Paul Jonas,
Schwenger Jan,
Torun Boray,
Grundmeier Guido,
Spiecker Erdmann,
Peukert Wolfgang
Publication year - 2017
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.15072
Subject(s) - materials science , nanocrystalline material , focused ion beam , anatase , amorphous solid , composite material , scanning electron microscope , transmission electron microscopy , mesoporous material , particle (ecology) , annealing (glass) , ceramic , deformation (meteorology) , nanoparticle , mineralogy , nanotechnology , crystallography , ion , biochemistry , chemistry , oceanography , photocatalysis , geology , catalysis , physics , quantum mechanics
The mechanical behavior of nanostructured spherical submicrometer titania particles was studied by in situ uniaxial compression experiments in the scanning and transmission electron microscope ( SEM and TEM ). Mesoporous and amorphous titania particles were prepared by a wet chemical sol‐gel approach. To obtain nanocrystalline (nc) single‐phase anatase and rutile particles the amorphous particles were crystallized by high‐temperature annealing. For each sample the deformation behavior of at least 50 particles was investigated by in situ compression experiments in the SEM . In all cases an elastic – predominantly plastic deformation behavior accompanied by crack initiation at exceptionally high engineering strain values of several percent were observed. Crack propagation presumably along grain boundaries and a Weibull distributed fracture stress was shown for all nc particles. Complementary in situ TEM experiments and ex situ analysis of focused ion beam prepared particle cross‐sections were carried out to identify the underlying deformation mechanisms. Grain rotations and grain sliding are observed for nc anatase particles during in situ compression and are further identified to be linked to a densification of the mesoporous particle structure. Our dedicated preparation and quantitative in situ characterization methodology provides an excellent basis for a better understanding of the mechanical behavior of advanced ceramics.