Research Study To Determine The Phase Equilibrium Relations Of Selected Metal Carbides At High Temperatures
Report Number: WADD TR 60-143
Author(s): Dolloff, R. T.
Corporate Author(s): Research Laboratory of National Carbon Company Division of Union Carbide Corporation
Laboratory: Materials Central
Date of Publication: 1960-07
Pages: 28
Contract: AF 33(616)-6286
DoD Project: 7350
DoD Task: 73500
PB Number: PB171365
Identifier: AD0244270
Abstract:
The work here reported is the result of an investigation of phase equilibria in the ternary system, silicon-boron-carbon. Techniques for extending the high temperature range of measurements have been developed. Accurate phase diagrams for the silicon-carbon and the boron-carbon binaries have been obtained and details of the ternary system have been determined in the high carbon content region. The data were obtained by high temperature differential thermal analysis and by photoelectric thermal analysis, both supplemented by metallographic, X-ray and chemical techniques.Results for the boron-carbon binary system indicate that boron melts at 2130 ± 10°C and that B4C has a congruent melting point of 2470 ± 20°C. Boron and B4C form a eutectic at 2080 ± 20°C, whereas carbon and B4C form a eutectic at 2390 ± 20°C. Results for the silicon-carbon binary indicate a eutectic between silicon and SiC at 1402 ± 5°C. SiC melts incongruently at 2540 ± 40°C. The peritectic point is located at 27 per cent carbon. Results for the ternary system indicate a eutectic between B4C, SiC and carbon at 2250 ± 20°C. No compound formation has been observed in the high carbon region of the ternary system.
Provenance: IIT
Author(s): Dolloff, R. T.
Corporate Author(s): Research Laboratory of National Carbon Company Division of Union Carbide Corporation
Laboratory: Materials Central
Date of Publication: 1960-07
Pages: 28
Contract: AF 33(616)-6286
DoD Project: 7350
DoD Task: 73500
PB Number: PB171365
Identifier: AD0244270
Abstract:
The work here reported is the result of an investigation of phase equilibria in the ternary system, silicon-boron-carbon. Techniques for extending the high temperature range of measurements have been developed. Accurate phase diagrams for the silicon-carbon and the boron-carbon binaries have been obtained and details of the ternary system have been determined in the high carbon content region. The data were obtained by high temperature differential thermal analysis and by photoelectric thermal analysis, both supplemented by metallographic, X-ray and chemical techniques.Results for the boron-carbon binary system indicate that boron melts at 2130 ± 10°C and that B4C has a congruent melting point of 2470 ± 20°C. Boron and B4C form a eutectic at 2080 ± 20°C, whereas carbon and B4C form a eutectic at 2390 ± 20°C. Results for the silicon-carbon binary indicate a eutectic between silicon and SiC at 1402 ± 5°C. SiC melts incongruently at 2540 ± 40°C. The peritectic point is located at 27 per cent carbon. Results for the ternary system indicate a eutectic between B4C, SiC and carbon at 2250 ± 20°C. No compound formation has been observed in the high carbon region of the ternary system.
Provenance: IIT