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Hot isostatic pressed pyrochlore glass‐ceramics: Revealing structure insides at the reaction interface
Author(s) -
Zhang Yingjie,
Wei Tao,
Xu Alan,
Dayal Pranesh,
Gregg Daniel J.
Publication year - 2021
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.17958
Subject(s) - materials science , hot isostatic pressing , pyrochlore , ceramic , microstructure , scanning electron microscope , oxide , transmission electron microscopy , zirconolite , glass ceramic , metallurgy , phase (matter) , composite material , chemical engineering , nanotechnology , chemistry , organic chemistry , engineering
As potential waste forms for immobilizing actinide‐rich radioactive wastes, Eu 2 Ti 2 O 7 (Eu as a surrogate for minor actinides) pyrochlore glass‐ceramics were fabricated via hot isostatic pressing (HIPing) at 1200°C. The structure and microstructure at the reaction interface between the glass‐ceramic waste form and the stainless steel (SS) canister under HIPing conditions were carefully investigated with scanning electron microscopy (SEM), transmission electron microscopy (TEM), and synchrotron single crystal X‐ray diffraction (SC‐XRD). The interactions at the reaction interface led to the formations of a ~10‐µm‐thick Cr 2 O 3 layer as the oxidation front of the SS and a layer of a mixed oxide phase (Eu 1.25 SiCr 0.8 Ti 1.2 O 7.5 ) on the glass‐ceramic side of the reaction interface. The crystal structure of such a unique mixed oxide phase was revealed indubitably with a combination of synchrotron SC‐XRD and TEM assisted with a focused ion beam (FIB) SEM system. The improved structural understanding of the reaction interface will help to support the utilization of HIPing as a versatile hot consolidation process for the treatment of radioactive wastes.