Improved silicon nitride for advanced heat engines. Annual Technical Report, 26 September 1984-30 September 1985

Technical Report · Tue Oct 01 04:00:00 EDT 1985

OSTI ID:5444067

Yeh, H C; Wimmer, J M; Huang, H H; Rorabaugh, M E; Schienle, J; Styhr, K H

The AiResearch Casting Company baseline silicon nitride (92 percent GTE SN-502 Si/sub 3/N/sub 4/ plus 6 percent Y/sub 2/O/sub 3/ plus 2 percent Al/sub 2/O/sub 3/) was characterized with methods that included chemical analysis, oxygen content determination, electrophoresis, particle size distribution analysis, surface area determination, and analysis of the degree of agglomeration and maximum particle size of elutriated powder. Test bars were injection molded and processed through sintering at 0.68 MPa (100 psi) of nitrogen. The as-sintered test bars were evaluated by x-ray phase analysis, room and elevated temperature modulus of rupture strength, Weibull modulus, stress rupture, strength after oxidation, fracture origins, microstructure, and density from quantities of samples sufficiently large to generate statistically valid results. A series of small test matrices were conducted to study the effects and interactions of processing parameters which included raw materials, binder systems, binder removal cycles, injection molding temperatures, particle size distribution, sintering additives, and sintering cycle parameters.

• Research Organization: AiResearch Casting Co., Torrance, CA (USA)
• OSTI ID: 5444067
• Report Number(s): N-88-15886; NASA-CR-175006; NAS-1.26:175006; REPT-85-22592
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
360201* -- Ceramics
Cermets
& Refractories-- Preparation & Fabrication
ALUMINIUM COMPOUNDS
ALUMINIUM OXIDES
CHALCOGENIDES
CHEMICAL ANALYSIS
CHEMICAL PREPARATION
CHEMICAL REACTIONS
CRYSTAL STRUCTURE
ELECTROPHORESIS
FABRICATION
MANUFACTURING
MECHANICAL PROPERTIES
MICROSTRUCTURE
NITRIDES
NITROGEN COMPOUNDS
OXIDATION
OXIDES
OXYGEN COMPOUNDS
PNICTIDES
SILICON COMPOUNDS
SILICON NITRIDES
SINTERING
SYNTHESIS
TEMPERATURE EFFECTS
TRANSITION ELEMENT COMPOUNDS
YTTRIUM COMPOUNDS
YTTRIUM OXIDES