Accession Number : ADD003837

Title :   Boron Carbide.

Descriptive Note : Patent,

Corporate Author : DEPARTMENT OF THE NAVY WASHINGTON D C

Personal Author(s) : Ditter,Jerome F ; Gerhart,Francis J ; Williams,Robert E

Report Date : 12 Apr 1977

Pagination or Media Count : 5

Abstract : This disclosure describes the process for producing an apparently amorphous porous boron carbide having a mean particle size less than 1 micron in diameter, effective pore sizes on the order of 30 Angstrom units, and surface areas on the order of 100 sq. m/gr and greater. The process involves the gaseous phase reaction of acetylene (C2H2) with diborane (B2H6). The reaction is produced in a closed chamber initiated by an appropriate igniting device, such as a hot wire. This disclosure defines an optimum ratio of four parts diborane to one part acetylene and it describes the operating conditions under which the reaction occurs and the variation in physical properties and yield resulting from changes of ratio of the constituents. It also describes modification of the present batch process to a continuous production process. Typical uses for the material in its basic or altered form are described, such as a catalyst for gassolid reactions, as a catalyst-supporting substrate for certain transition metals and other catalytic materials, as a gelling agent or grease thickener, as a thermal neutron absorber, either neat or in admixture with oils, etc., as a high temperature insulation material and as a fluidized bed heat exchange medium. (Author)

Descriptors :   *Patents, *Boron carbides, *Processing, *Catalysts, *Substrates, *Porous materials, Amorphous materials, Surfaces, Absorbers(Materials), Chemical reactions, Acetylene, Diboranes

Subject Categories : Physical Chemistry
      Mfg & Industrial Eng & Control of Product Sys

Distribution Statement : APPROVED FOR PUBLIC RELEASE