NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Tensile Behavior of As-Fabricated and Burner-Rig Exposed SiC/SiC Composites with Hi-Nicalon Type-S FibersTensile stress-strain curves were measured at room temperature and 1315 C for 2D-woven SiC/BN/SiC ceramic matrix composites (CMC) reinforced by two variations of Hi-Nicalon Type-S SiC fibers. These fibers, which contained a thin continuous carbon-rich layer on their as-produced surface, provided the as-fabricated CMC with good composite behavior and an ultimate strength and strain of -350 MPa and -0.5%, respectively. However, after un-stressed burner-rig exposure at 815 C for -100 hrs, CMC tensile specimens with cut edges and exposed interphases showed a significant decrease in ultimate properties with effectively no composite behavior. Microstructural observations show that the degradation was caused by internal fiber-fiber oxide bonding after removal of the carbon-rich fiber surface layer by the high-velocity combustion gases. On the other hand, SiC/BN/SiC CMC with Sylramic-iBN fibers without carbon-rich surfaces showed higher as-fabricated strength and no loss in strength after the same burner rig exposure. Based on the strong role of the carbon layer in these observations, a process method was developed and demonstrated for achieving better strength retention of Hi-Nicalon Type-S CMC during burner rig exposure. Other general approaches for minimizing this current deficiency with as-produced Type-S fibers are discussed.
Document ID
20120009033
Acquisition Source
Glenn Research Center
Document Type
Conference Paper
Authors
Yun, H. M.
(National Academy of Sciences - National Research Council Washington, DC, United States)
Dicarlo, J. A.
(NASA Glenn Research Center Cleveland, OH, United States)
Ogbuji, L. T.
(National Academy of Sciences - National Research Council Washington, DC, United States)
Chen, Y. L.
(National Academy of Sciences - National Research Council Washington, DC, United States)
Date Acquired
August 25, 2013
Publication Date
January 21, 2002
Publication Information
Publication: 26th Annual Conference on Composites, Advanced Ceramics, Materials, and Structures: A: Ceramic Engineering and Science Proceedings
Volume: 23
Issue: 3
Subject Category
Composite Materials
Meeting Information
Meeting: 26th Annual International Conference on Advanced Ceramics and Composites
Location: Cocoa Beach, FL
Country: United States
Start Date: January 21, 2002
End Date: January 26, 2002
Sponsors: American Ceramic Society
Distribution Limits
Public
Copyright
Other

Available Downloads

There are no available downloads for this record.
No Preview Available