Oxidation of Non-Oxide Ceramics.

reportActive / Technical Report | Accession Number: ADA115947 | Open PDF

Abstract:

Oxidation mechanisms of SiC were determined. It was found that cristobalite nucleates at the SiCSiO2 interface with appreciable heterogeneous nucleation during the first hour. Identical oxidation mechanisms were found for both single crystal and sintered polycrystalline SiC. Oxidation of yttria stabilized silicon nitride was investigated to determine the cause of the catastrophic oxidation at 1000C. At high temperature, SiO2 covers the entire surface, but at low temperature it does not. This allows the unstable yttria silicon oxynitride phases to form and cause catastrophic failure. No evidence of the effect of tungsten was noted. Author

Author(s):
Mitchell, T. E. ; Heuer, A. H.
Author Organization(s):
CASE WESTERN RESERVE UNIV CLEVELAND OH DEPT OF METALLURGY AND MATERIALS SCIENCE
Descriptive Note:
Final rept. Feb 75-Feb 82,
Pagination:
0022

Security Markings

DOCUMENT & CONTEXTUAL SUMMARY

Distribution:
Approved For Public Release

RECORD

Collection: TR
Identifying Numbers
Report Number(s):
AFOSR-TR-82-0482
Contract/Grant Number(s):
F49620-78-C-0053
Task Number(s):
A1
Project Number(s):
2305
Monitor Series:
TR-82-0482
 Subject Terms
Joint Capability Areas:
JCA_5_Command and Control; JCA_5.3_Planning; JCA_3.2_Engagement; JCA_3_Force Application; JCA_6_Net Centric; JCA_3.2.1_Kinetic Means; JCA_1.2_Force Preparation; JCA_1_Force Support; JCA_6.1_Information Transport; JCA_1.2.3_Educating
Modernization Areas:
Microelectronics
Communities of Interest:
No COI(s) Identified
Descriptor(s):
*Ceramic materials, *Silicon compounds, *Oxidation, *Single crystals, Tracer studies, Oxygen, Silicon carbides, Silicon nitrides, Sintering, Grain growth, Porosity, Spherulites, Diffusion, Equilibrium(General), Polycrystalline, Nucleation, Electron microscopy
Field(s)/Group(s):
Physical Chemistry, Ceramics, Refractories and Glass, Crystallography
Keyword(s):
PE61102F, WUAFOSR2305A1
Report Date:
1982 May 25