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Preparation, Hardness, and Fracture Toughness of Tantalum Oxynitride Ceramics
Author(s) -
Matizamhuka Wallace R.,
Herrmann Mathias,
Sigalas Iakovos,
Sempf Kerstin
Publication year - 2007
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/j.1551-2916.2007.01697.x
Subject(s) - materials science , tantalum , fracture toughness , hot pressing , ceramic , composite material , metallurgy
Tantalum oxynitride powder with a baddeleyite crystal structure was synthesized and densified by hot pressing in Ar and under high pressure using a belt‐type high‐pressure apparatus. The tantalum oxynitride powder could not be densified completely under hot‐pressing conditions at 1400°C. The use of high pressure resulted in dense materials. The samples showed a hardness of 16–17 GPa and a fracture toughness of 3–4 MPa·m 1/2 . The hardness is higher compared with that of ZrO 2 and HfO 2 ceramics. The fracture toughness corresponds to the value of fully stabilized ZrO 2 due to the absence of any transformation toughening mechanism.