Accession Number : AD0813888

Title :   DEVELOPMENT ON HIGH TEMPERATURE INSULATION MATERIALS.

Descriptive Note : Quarterly rept. no. 7, 1 Dec 66-28 Feb 67,

Corporate Author : WESTINGHOUSE RESEARCH LABS PITTSBURGH PA

Personal Author(s) : Lewis,D. W. ; Esposito,J. N. ; Dakin,T. W. ; Berg,D.

Report Date : 28 FEB 1967

Pagination or Media Count : 29

Abstract : Coatings of aluminum nitride were deposited on molybdenum substrates at pressures of 5 to 10 torr and 1000 to 1200 C, using aluminum chloride and ammonia as starting materials. Deposition rate was greater and the coatings were smoother than those previously deposited at atmospheric pressure. Electrical properties of the coatings deposited at 1100 C are about the same as earlier deposits. The characterization of silicon nitride films produced by the reduced pressure pyrolysis of silane and ammonia is progressing. Data on the elemental composition and impurity levels have been gathered and exposure of the coated molybdenum samples to air at 1000 C has shown the thin films to be relatively pinhole free. The composition of the transition layer between the molybdenum substrate and the silicon nitride coating has been shown to consist primarily of gamma -MoN2 with the presence of alpha -Si3N4 and the possible presence of MoSi2 also indicated by the x-ray data. (Author)

Descriptors :   (*COATINGS, *THERMAL INSULATION), (*NITRIDES, DEPOSITION), PYROLYSIS, SUBSTRATES, MOLYBDENUM ALLOYS, ALUMINUM COMPOUNDS, SILICON COMPOUNDS, VACUUM APPARATUS, SILANES, CHLORIDES, AMMONIA

Subject Categories : Coatings, Colorants and Finishes
      Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE