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Influence of Precursor Densification on Strength Retention of Zirconia‐Coated Nextel ™ 610 Fibers
Author(s) -
Bockmeyer Matthias J.,
Krüger Reinhard
Publication year - 2008
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.1551-2916.2008.02282.x
Subject(s) - materials science , cubic zirconia , composite material , porosity , fiber , degradation (telecommunications) , calcination , annealing (glass) , amorphous solid , phase (matter) , weibull modulus , stress (linguistics) , flexural strength , ceramic , catalysis , telecommunications , biochemistry , chemistry , linguistics , philosophy , organic chemistry , computer science
Strength degradation of Nextel ™ 610 fibers by continuous liquid phase coating was investigated for four different zirconia precursors. The precursors differed regarding their chemical composition (with or without yttrium), phase composition (amorphous or crystalline), and decomposition behavior. Phase transformation and densification of the films were characterized and found to depend on the kind of precursor. Single fiber Weibull's strength was measured for calcination temperatures between 250° and 1150°C for all precursors. Each precursor had an individual degradation behavior. For an annealing temperature of 1150°C highly damaged (∼1600 MPa) and undamaged (>3300 MPa) fibers were obtained depending on the kind of precursor. Fiber degradation could be correlated to mechanical stresses. Stress concentration due to inhomogeneous film thickness distribution is proposed as the cause of fiber strength degradation. Full strength could be retained for porous coatings or coatings where stresses were reduced by phase transformation.