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Creep of Duplex Microstructures
Author(s) -
French Jonathan D.,
Zhao Junhong,
Harmer Martin P.,
Chan Helen M.,
Miller Gary A.
Publication year - 1994
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.1151-2916.1994.tb04515.x
Subject(s) - creep , microstructure , materials science , composite material , composite number , ceramic , duplex (building) , phase (matter) , grain size , grain boundary , ultimate tensile strength , chemistry , dna , biochemistry , organic chemistry
The tensile creep behavior of two ceramic composite systems exhibiting duplex microstructures was studied relative to their single‐phase constituents in the temperature and stress ranges of 1100–1350°C and 35–75 MPa. The equivolumetric compositions in the Al 2 O 3 : c –ZrO 2 (8 mol% Y 2 O 3 ) and Al 2 O 3 :Y 3 Al 5 O 12 systems both exhibit lower creep rates than either of their single‐phase constituents. This effect is attributed to Y 3+ (and possibly Zr 4+ ) present in the A1 2 O 3 as a segregant which lowers the creep rate by ∼2 orders of magnitude. It is believed that the segregation of Y 3+ to the A1 2 O 3 grain boundaries hinders the interface reaction believed to control the creep. If one of the single‐phase constituents is taken to be the Y 3+ ‐doped Al 2 O 3 , the creep of the duplex microstructures can be modeled using standard composite theory applied to flow.