CVD silicon carbide characterization. Final report, August 1992-October 1993
Abstract
Chemically vapor deposited (CVD) silicon carbide is a candidate material for high quality ground and space-based mirror substrates and high quality reflective optics. Statistically valid material property data has not been available, however, to make durability and lifetime predictions for such optics. The primary purpose of this study was to determine the Weibull and slow crack growth parameters for CVD silicon carbide. Specimens were cut from various locations in a 25 mm thick, 50 cm diameter piece of SiC to analyze bulk material property homogeneity. Flexural strength was measured using a four-point bend technique. In addition to mechanical testing for strength, hardness, and fracture toughness, the material crystallography and microstructure were studied. Thermal expansion, thermal diffusivity, specific heat, optical absorption, and infrared reflectivity measurements were also conducted. Raman spectroscopy was used to check for any residual stress. Test results show this CVD silicon carbide is a high-purity, homogeneous, fine-grained substrate material with very good mechanical, optical, and thermal properties.
- Authors:
- Publication Date:
- Research Org.:
- Dayton Univ., OH (United States). Research Inst.
- OSTI Identifier:
- 7084619
- Report Number(s):
- AD-A-285667/2/XAB; UDR-TR-93-122
CNN: F30602-90-D-0105
- Resource Type:
- Technical Report
- Country of Publication:
- United States
- Language:
- English
- Subject:
- 36 MATERIALS SCIENCE; SILICON CARBIDES; CHEMICAL VAPOR DEPOSITION; FLEXURAL STRENGTH; FRACTURE PROPERTIES; THERMAL EXPANSION; CRACK PROPAGATION; CRACKS; FATIGUE; HARDNESS; MICROHARDNESS; MICROSTRUCTURE; PROGRESS REPORT; SPECIFIC HEAT; THERMAL DIFFUSIVITY; CARBIDES; CARBON COMPOUNDS; CHEMICAL COATING; DEPOSITION; DOCUMENT TYPES; EXPANSION; MECHANICAL PROPERTIES; PHYSICAL PROPERTIES; SILICON COMPOUNDS; SURFACE COATING; THERMODYNAMIC PROPERTIES; 360203* - Ceramics, Cermets, & Refractories- Mechanical Properties; 360204 - Ceramics, Cermets, & Refractories- Physical Properties
Citation Formats
Graves, G A, and Iden, D. CVD silicon carbide characterization. Final report, August 1992-October 1993. United States: N. p., 1994.
Web.
Graves, G A, & Iden, D. CVD silicon carbide characterization. Final report, August 1992-October 1993. United States.
Graves, G A, and Iden, D. 1994.
"CVD silicon carbide characterization. Final report, August 1992-October 1993". United States.
@article{osti_7084619,
title = {CVD silicon carbide characterization. Final report, August 1992-October 1993},
author = {Graves, G A and Iden, D},
abstractNote = {Chemically vapor deposited (CVD) silicon carbide is a candidate material for high quality ground and space-based mirror substrates and high quality reflective optics. Statistically valid material property data has not been available, however, to make durability and lifetime predictions for such optics. The primary purpose of this study was to determine the Weibull and slow crack growth parameters for CVD silicon carbide. Specimens were cut from various locations in a 25 mm thick, 50 cm diameter piece of SiC to analyze bulk material property homogeneity. Flexural strength was measured using a four-point bend technique. In addition to mechanical testing for strength, hardness, and fracture toughness, the material crystallography and microstructure were studied. Thermal expansion, thermal diffusivity, specific heat, optical absorption, and infrared reflectivity measurements were also conducted. Raman spectroscopy was used to check for any residual stress. Test results show this CVD silicon carbide is a high-purity, homogeneous, fine-grained substrate material with very good mechanical, optical, and thermal properties.},
doi = {},
url = {https://www.osti.gov/biblio/7084619},
journal = {},
number = ,
volume = ,
place = {United States},
year = {Mon Aug 01 00:00:00 EDT 1994},
month = {Mon Aug 01 00:00:00 EDT 1994}
}