Accession Number:

AD0625336

Title:

HEATS OF FORMATION OF METALLIC BORIDES BY FLUORINE BOMB CALORIMETRY

Descriptive Note:

Final rept. 1 Oct 1963-30 Jun 1965

Corporate Author:

NATIONAL BUREAU OF STANDARDS GAITHERSBURG MD

Personal Author(s):

• Domalski, Eugene S.
• Armstrong, George T.

Report Date:

1965-10-01

Pagination or Media Count:

56.0

Abstract:

The purpose was to provide heat of formation data on boron and intermetallic borides applicable to calculations involving the combustion of slurry fuels. The heats of formation of BF3g, CF4g, B4Cc, AlB2.215c, alphaAlB12c and gamma-AlB12c were calculated from the heats of combustion of boron, graphite, B4Cc, AlB2.215 c, alpha-AlB12c and gamma-AlB12c in fluorine at high pressures. The heat measurements were made in a bomb calorimeter. The samples were subjected to thorough analysis and careful characterization. Three different methods were used to prepare pelleted mixtures of the samples with Teflon powder for combustion. The completeness of combustion was determined by analysis of the unburned sample remaining in the bomb after an experiment. The heats of combustion in fluorine at 298K and the corresponding standard deviations of the means are given, along with the substances for which they were determined. The standard heats of formation at 298K and the estimated over-all accuracies are also given.

Descriptors:

• *HEAT OF FORMATION
• GRAPHITE
• CARBIDES
• COMBUSTION
• FLUORINE
• BORON
• HEAT OF COMBUSTION
• METAL COMPOUNDS
• BORIDES
• CARBON COMPOUNDS
• BORON COMPOUNDS
• ALUMINUM COMPOUNDS
• FLUORIDES

Subject Categories:

• Physical Chemistry

Distribution Statement:

APPROVED FOR PUBLIC RELEASE