Accession Number : ADA264474


Title :   Effect of Powder Processing on Slip Casting Parameters and Sintering of Si3N4(-)Y2O3(-)SiO2


Descriptive Note : Final rept.


Corporate Author : ARMY RESEARCH LAB WATERTOWN MA MATERIALS DIRECTORATE


Personal Author(s) : Gilde, Gary ; Gazza, George


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a264474.pdf


Report Date : Apr 1993


Pagination or Media Count : 15


Abstract : A procedure was developed for slip casting Si3N4(-)Y2O3(-)SiO2 compositions. Thesilicon nitride was oxidized to supply the silica. The procedure resulted in 65 w/o slips with viscosities of 35 mPa(dot)s which, when cast, yielded compacts which were 56% of theoretical density. Slips with 70 w/o solids loading were also prepared having viscosities of 120 mPa(dot)s. The properties of the slips were influenced by the starting silicon nitride powder, dispersant, and milling media. The resulting compacts could be gas pressure sintered to full density, at temperatures as low as 1850 deg C, using nitrogen pressures as low as 4 MPa. Strengths as high as 750 MPa were achieved and the initial results show good creep resistance at 1350 deg C. Silicon nitrides, Slip casting, Oxidation, Sintering, Dispersants, Silica.


Descriptors :   *SILICON DIOXIDE , *POWDERS , *YTTRIUM OXIDES , *SLIP CASTING , *SINTERING , *SILICON NITRIDES , DENSITY , RESISTANCE , NITROGEN , CHEMICAL COMPOSITION , PRESSURE , MEDIA , VISCOSITY , SUPPLIES , CREEP , OXIDATION , GASES , SOLIDS , DISPERSANTS , TEMPERATURE


Subject Categories : Inorganic Chemistry
      Physical Chemistry
      Fabrication Metallurgy
      Solvents, Cleaners, and Abrasives


Distribution Statement : APPROVED FOR PUBLIC RELEASE