Accession Number : ADA194690

Title :   A Study of Impurities in Combustion Synthesis Systems.

Descriptive Note : Memorandum rept.,

Corporate Author : ARMY BALLISTIC RESEARCH LAB ABERDEEN PROVING GROUND MD

Personal Author(s) : Kecskes, Laszlo J ; Niiler, Andrus

PDF Url : ADA194690

Report Date : Apr 1988

Pagination or Media Count : 56

Abstract : This investigation is directed toward a detailed understanding of the nature of the evolution of solid and gaseous impurities during the Combustion Synthesis (Self-Propagating High Temperature Synthesis) of ceramic materials. The identities and amounts of the volatile impurities present on various reactant powders were measured and the effects of storage and handling conditions evaluated using a vacuum furnace and a Residual Gas Analyzer. The extent to which these impurities volatilize, react with each other, and affect the reaction dynamics and product structure were analyzed for the titanium+carbon system. The result indicate that the major volatile impurity species on the reactant powders are water vapor, hydrogen, carbon monoxide, carbon dioxide, and hydrocarbons. Further Residual Gas Analysis, Scanning Electron Microscopy, and Ion Beam Analyses reveal marked differences in both non-condensible and condensible impurity species evolved by the reacting Ti+C system. It is found that the physical and mechanical properties of the ceramic material will be significantly improved if the impurities are eliminated with a 500C vacuum bakeout.

Descriptors :   *CERAMIC MATERIALS, *COMBUSTION, ANALYZERS, CARBON DIOXIDE, CARBON MONOXIDE, CONDENSATION, DYNAMICS, ELECTRON MICROSCOPY, ELECTRONIC SCANNERS, EVOLUTION(GENERAL), GAS ANALYSIS, GASES, HANDLING, HYDROCARBONS, HYDROGEN, IMPURITIES, ION BEAMS, MECHANICAL PROPERTIES, PHYSICAL PROPERTIES, POWDERS, REACTANTS(CHEMISTRY), RESIDUALS, RESPONSE, SOLIDS, STORAGE, VACUUM FURNACES, VOLATILITY, WATER VAPOR

Subject Categories : Ceramics, Refractories and Glass
      Combustion and Ignition

Distribution Statement : APPROVED FOR PUBLIC RELEASE