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Microstructure evolution of a W‐doped ZrB 2 ceramic upon high‐temperature oxidation
Author(s) -
Silvestroni Laura,
Sciti Diletta,
Monteverde Frédéric,
Stricker Kerstin,
Kleebe HansJoachim
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.14738
Subject(s) - microstructure , ceramic , materials science , transmission electron microscopy , nanostructure , doping , oxygen , chemical engineering , composite material , metallurgy , nanotechnology , mineralogy , chemistry , optoelectronics , organic chemistry , engineering
This basic research deals with the microstructure evolution of a W‐doped ZrB 2 ceramic, as‐sintered and upon oxidation at 1650°C. Transmission electron microscopy enabled to disclose microstructural features occurred during oxidation never observed before. In the pristine material, (Zr,W)B 2 solid solutions surround the original ZrB 2 nuclei, whereas refractory W‐compounds at triple junctions and clean grain boundaries are distinctive of this ceramic. After oxidation, the microstructure is typified by intragranular nanostructures, in which nanosized W inclusions remained trapped within ZrO 2 grains, or decorate their surfaces. The understanding of the oxidation reactions occurring in the system as a function of the oxygen partial pressure was fundamental to conclude that W‐based compounds do not notably suppress or retard the oxidation of ZrB 2 ceramics.