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Zirconia–Silica–Carbon Coatings on Ceramic Fibers
Author(s) -
Boakye Emmanuel E.,
Hay Randall S.,
Petry M. Dennis,
Parthasarathy Triplicane A.
Publication year - 2004
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.1151-2916.2004.tb06348.x
Subject(s) - materials science , cubic zirconia , composite material , ceramic , fiber , ultimate tensile strength , ceramic matrix composite , zircon , carbon fibers , chemical engineering , composite number , paleontology , engineering , biology
Precursors for zircon–carbon mixtures were made to coat fibers for ceramic‐matrix composites. Precursors were characterized using XRD, TGA, and DTA. Zircon formed from vanadium‐ or lithium‐doped precursors after heat treatments at ≥900°C in air, but it did not form at 1200°–1400°C in argon when large amounts of carbon were added. Some precursors were used to coat Nextel™ 720 and Hi‐Nicalon™ fibers. The coatings were characterized using SEM and TEM, and coated‐fiber tensile strengths were measured. Although zircon formed in powders, only tetragonal‐zirconia–silica mixed phases formed in fiber coatings at 1200°C in air. Loss of vanadium oxide flux to the fibers may have caused the lack of conversion to zircon. The strengths of the coated fibers were severely degraded after heat treatment at ≥1000°C in air, but not in argon. The coated fibers were compared with zirconia–carbon‐coated fibers made using similar methods. Mechanisms for fiber strength degradation are discussed.