Accession Number : AD0693882

Title :   CHEMICAL VAPOR DEPOSITION OF BORON CARBIDE.

Descriptive Note : Final rept. 1 Jul 68-30 Jun 69,

Corporate Author : UNION CARBIDE CORP PARMA OHIO CARBON PRODUCTS DIV

Personal Author(s) : Moore,Arthur W. ; Volk,Herbert F.

Report Date : AUG 1969

Pagination or Media Count : 45

Abstract : The chemical vapor deposition of boron carbide (B4C) was studied with the objective of preparing unusually hard specimens. Diamond pyramid microhardnesses at 100 gram load as high as 4800 kg/sq mm (20 percent greater than the value of 4000 kg/sq mm for hot-pressed B4C) were obtained on deposits prepared from BCl3 and CH4 at 2000-2100C. Massive specimens of such deposits could not be produced, but thick deposits were obtained at 1300C using a large excess of H2 and CH4 with the BCl3. Hardness and modulus of these low temperature deposits were normal (4000 kg/sq mm and 58,000,000 lb/sq in., respectively), and were not increased by thermal annealing. Doping of B4C with silicon or titanium had no substantial effect on hardness. (Author)

Descriptors :   (*CERAMIC MATERIALS, *VAPOR PLATING), (*BORON COMPOUNDS, CARBIDES), HARDNESS, DOPING, SILICON, TITANIUM

Subject Categories : Ceramics, Refractories and Glass
      Fabrication Metallurgy

Distribution Statement : APPROVED FOR PUBLIC RELEASE