Accession Number : ADA253450


Title :   Oxidation Protection Systems for Carbon-Carbon Composites Formed by Chemical Vapor Deposition and Plasma Assisted Chemical Vapor Deposition Techniques


Descriptive Note : Final rept. 1 Mar 1988-28 Feb 1991


Corporate Author : SOUTHERN ILLINOIS UNIV AT CARBONDALE MATERIALS TECHNOLOGY CENTER


Personal Author(s) : Shi, Y ; Stojak, J ; He, J ; Don, J ; Wright, M A


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a253450.pdf


Report Date : 22 Apr 1992


Pagination or Media Count : 388


Abstract : A final report written in three sections. (1) 'CVI Densification of Carbon-Carbon Composites' deals with the densification of porous preforms of carbonized carbon-resin mixtures using various methane and hydrogen gas mixtures. The experimental conditions include temperatures between 1000 deg C and 1200 deg C and total pressures between 5 and 15 torr. The resulting solid was characterized using optical and electron microscopy. (2) 'Oxidation Protection of Carbon-Carbon Composites Using Pack Cementation' deals with formation of oxidation protective films formed from combinations of boron carbide, silicon carbide and zirconium carbide. Films were processed using a reactive process called pack cementation. The effects of initial powder composition and temperature were correlated with microstructure and oxidation resistance. (3) In 'The Formation of Oxidation Protective Coatings on Carbon- Carbon Composites Using a Chemical Vapor Deposition (CVD) Technique four types of CVD coatings were investigated: SiC, ZrB ZrB /SiC multilayer and graded SrC/ZrC. Coatings were produced as a function of temperature, pressure and gas flow rates. The resulting coatings were then characterized in terms of microstructure and oxidation resistance. OXIDATION RESISTANCE, CHEMICAL VAPOR DEPOSITION, CARBON-CARBON.


Descriptors :   *CHEMICALS , *VAPOR DEPOSITION , *COATINGS , *PROTECTION , *PROTECTIVE COATINGS , *OXIDATION , *CARBON CARBON COMPOSITES , FUNCTIONS , DENSITY , VAPORS , RESISTANCE , CARBIDES , SOLIDS , MIXTURES , OXIDATION RESISTANCE , FLOW , BORON CARBIDES , ZIRCONIUM , PRESSURE , SILICON , FLOW RATE , ELECTRONS , DEPOSITION , OPTICAL INSTRUMENTS , GAS FLOW , SILICON CARBIDES , STRONTIUM , PLASTICS , BORON , METHANE , HYDROGEN , CARBON , RATES , FILMS , POWDERS , TEMPERATURE , MICROSTRUCTURE


Subject Categories : Physical Chemistry
      Electrooptical and Optoelectronic Devices
      Coatings, Colorants and Finishes
      Laminates and Composite Materials


Distribution Statement : APPROVED FOR PUBLIC RELEASE