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Intergranular amorphous films formed by DC electric field in pure zirconia
Author(s) -
Morisaki Nobuhiro,
Yoshida Hidehiro,
Kobayashi Tetsuro,
Tokunaga Tomoharu,
Yamamoto Takahisa
Publication year - 2018
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.15485
Subject(s) - materials science , sintering , monoclinic crystal system , amorphous solid , tetragonal crystal system , cubic zirconia , transmission electron microscopy , electric field , composite material , spark plasma sintering , mineralogy , analytical chemistry (journal) , crystallography , ceramic , nanotechnology , crystal structure , chemistry , physics , quantum mechanics , chromatography
It is difficult to obtain pure ZrO 2 sintered compacts with a bulk style at room temperature because a large volumetric expansion from tetragonal to monoclinic phase ( t / m ) transformation occurs at around 1000°C, which is lower than the sintering temperature. In contrast, pure monoclinic ZrO 2 can be consolidated without shattering using flash‐sintering at 1350°C for 5 minutes under an applied DC electric field of 175 V/cm. High‐resolution transmission electron microscopy and electron energy loss spectroscopy have revealed that amorphous films are formed along grain boundaries after flash‐sintering at 1350°C for 5 minutes. Monoclinic ZrO 2 flash‐sintered compact including the amorphous films are able to survive without shattering through the t / m transformation, as the amorphous films partially absorb the large volumetric expansion arising from the t / m transformation. The formation of the amorphous films results from the severe reducing condition due to the applied DC electric fields during flash‐sintering.