Accession Number : ADA563908


Title :   Oxidation Resistance, Electrical and Thermal Conductivity, and Spectral Emittance of Fully Dense HfB2 and ZrB2 with SiC, TaSi2, and LaB6 Additives


Descriptive Note : Final rept. 1 Aug 2008-14 Sep 2011


Corporate Author : GEORGIA INST OF TECH ATLANTA SCHOOL OF MATERIALS SCIENCE AND MECHANICAL ENGINEERING


Personal Author(s) : Speyer, Robert F


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a563908.pdf


Report Date : 26 Jan 2012


Pagination or Media Count : 100


Abstract : The oxidation resistances of ZrB2 containing SiC, TaB2, and TaSi2 additions of various concentrations were studied using isothermal thermogravimetry at 1200, 1400, and 1500 deg C. Theoretically-dense ZrB2-SiC two-phase microstructures were isothermally oxidized for 90 min in a thermogravimetric analyzer in flowing air in the range 1500-1900 deg C. The oxidation resistances of theoretically-dense HfB2-SiC test specimens were evaluated via isothermal thermogravimetry at 1600, 1700 and 1800 deg C. The thermal diffusivities of theoretically dense ZrB2-SiC (10.7, 21.9, or 48.7 vol% SiC) sintered/HIPed with B4C sintering aid was measured using the laser flash technique. Spectral emittances of direct electrically-heated ZrB2-30 mol% SiC specimens were measured in the 1-6 micrometer range.


Descriptors :   *ADDITIVES , *ELECTRICAL CONDUCTIVITY , *OXIDATION RESISTANCE , *SPECTRAL EMITTANCE , *THERMAL CONDUCTIVITY , HIGH DENSITY , ISOTHERMS , MICROSTRUCTURE , THERMAL DIFFUSION , THERMOGRAVIMETRIC ANALYSIS , TWO PHASE FLOW


Subject Categories : Physical Chemistry
      Electricity and Magnetism
      Thermodynamics


Distribution Statement : APPROVED FOR PUBLIC RELEASE