Accession Number : ADA001012


Title :   Ceramic Sintering


Descriptive Note : Semi-annual technical rept. 1 Apr-31 Oct 1974


Corporate Author : GENERAL ELECTRIC CORPORATE RESEARCH AND DEVELOPMENT SCHENECTADY NY


Personal Author(s) : Rosolowski, Joseph H ; Greskovich, Charles D


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a001012.pdf


Report Date : Oct 1974


Pagination or Media Count : 66


Abstract : Measurement of the rate of oxidation and creep rate in air of chemically vapor deposited Si3N4 at around 1500C are reported. Attempts to prepare pure, dense Si3N4 bodies by hot pressing powder at ultra-high pressures were unsuccessful. Resistance heaters made of dense, sintered SiC were tested and found to have in-use lifetimes very much longer than those of commercially available heaters tested in the same way. Microscopic examination of the structures developed during the initial stage sintering of SiC doped with C and B indicates that these dopants inhibit surface diffusion until densification begins at around 1500C. Bodies of B4C having about 94% of theoretical density were made by using conventional sintering processes and doping the powder with either SiC or Be4C.


Descriptors :   *BORON CARBIDES , *SILICON CARBIDES , *SILICON NITRIDES , *SINTERING , ADDITIVES , BERYLLIUM COMPOUNDS , CREEP , ELECTRIC HEATERS , HIGH TEMPERATURE , HOT PRESSING , OXIDATION , VAPOR DEPOSITION


Subject Categories : Ceramics, Refractories and Glass


Distribution Statement : APPROVED FOR PUBLIC RELEASE