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Experimental Evaluation of Toughening Mechanisms in Alumina‐Zirconia Composites
Author(s) -
Shin YuSeon,
Rhee YoungWoo,
Kang SukJoong L.
Publication year - 1999
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.1151-2916.1999.tb01900.x
Subject(s) - toughening , materials science , monoclinic crystal system , composite number , composite material , cubic zirconia , fracture toughness , grain size , ceramic , crystal structure , crystallography , chemistry , toughness
The contributions of transformation toughening and microcrack toughening in an 85Al 2 O 3 15ZrO 2 (vol%) composite were quantitatively evaluated. Three types of hot‐pressed samples with similar size (∼0.5 µm) and size distribution of ZrO 2 grains, but with different contents (vol%) of monoclinic‐ ( m ‐) ZrO 2 (0 (AZS), 45 (AZT), and 67 (AZM)) were prepared using Y 2 O 3 and MoO 2 dopants. Therefore, the possible effect of ZrO 2 grain size on each toughening mechanism was eliminated. When the measured fracture toughnesses of m ‐ZrO 2 volume fractions before and after fracture were compared, the transformation‐toughening constant was estimated as 3.0 MPam 1/2 and the microcrack‐toughening constant 0.2 MPam 1/2 for a 100% monoclinic transformation of ZrO 2 grains. This result indicates that transformation toughening was the dominant toughening mechanism in the studied composite.