In situ Y2Si2O7 coatings on Hi‐Nicalon‐S SiC fibers: Phase formation and fiber strength

Y2Si2O7 coatings were formed on Hi‐Nicalon‐S SiC fibers by reaction of solution‐derived YPO4 coatings with glass SiO2 scales formed by fiber oxidation. Two oxidation methods were used: pre‐oxidation, where fibers were oxidized prior to YPO4 coating, or post‐oxidation, where fibers were first coated...

Full description

Saved in:
Bibliographic Details
Published in:Journal of the American Ceramic Society 2019-10, Vol.102 (10), p.5725-5737
Main Authors: Boakye, Emmanuel E., Mogilevsky, Pavel, Key, Thomas S., Parthasarathy, Triplicane A., Keller, Kristin A., Opeka, Samuel J., Hay, Randall S., Cinibulk, Michael K., Corns, Randall
Format: Article
Language:English
Subjects:
Argon
ceramic matrix composites
Coatings
Comparative studies
Fiber strength
Fibers
Nicalon (trademark)
Oxidation
oxidation resistance
Reaction kinetics
Scale (corrosion)
Silicon carbide
Silicon dioxide
Thickness
Yttrium phosphate
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:Y2Si2O7 coatings were formed on Hi‐Nicalon‐S SiC fibers by reaction of solution‐derived YPO4 coatings with glass SiO2 scales formed by fiber oxidation. Two oxidation methods were used: pre‐oxidation, where fibers were oxidized prior to YPO4 coating, or post‐oxidation, where fibers were first coated with YPO4 and then oxidized. Fibers with YPO4/SiO2 films were heat‐treated in argon at 1200°C for 20 hours to react YPO4 and SiO2 to Y2Si2O7. The effects of SiO2 to YPO4 film thicknesses on fiber strength and on the Y2Si2O7formation kinetics were investigated. An optimized process to obtain single‐phase continuous Y2Si2O7 coatings on Hi‐Nicalon‐S fibers with low loss in fiber strength is suggested.
ISSN:0002-7820
1551-2916
DOI:10.1111/jace.16428