Research Study To Determine The Phase Equilibrium Relations Of Selected Metal Carbides At High Temperatures
Report Number: WADD TR 60-143 Part II
Author(s): Dolloff, R. T., Sara, R. V.
Corporate Author(s): Research Laboratory of National Carbon Company Division of Union Carbide Corporation
Laboratory: Directorate of Materials and Processes
Date of Publication: 1961-05
Pages: 25
Contract: AF 33(616)-6286
DoD Project: 7350
Identifier: AD0278009
Abstract:
The work here reported is the result of an investigation of phase equilibria in the binary system, tungsten-carbon. A tentative phase diagram is presented which differs significantly from the one proposed by Sykes in 1930 and which is generally accepted today. The data were obtained by high-temperature differential thermal analysis and classical quenching procedures, both supplemented by metallographic, x-ray, and chemical techniques.Results for the tungsten-carbon binary system indicate a eutectic between W and W2C at 2735°C, and a eutectic between W5C3 and C at 2765°C. The W2C lattice accommodates 72 and 74 atomic per cent W at 2475° and 2735°C, respectively. Carbon solubility is evident only at 2540°C, the eutectoid temperature. A new phase, W5C3, was discovered which is stable only above 2540°C. WC decomposes at 2730°C into W5C3 and C.
Provenance: IIT
Author(s): Dolloff, R. T., Sara, R. V.
Corporate Author(s): Research Laboratory of National Carbon Company Division of Union Carbide Corporation
Laboratory: Directorate of Materials and Processes
Date of Publication: 1961-05
Pages: 25
Contract: AF 33(616)-6286
DoD Project: 7350
Identifier: AD0278009
Abstract:
The work here reported is the result of an investigation of phase equilibria in the binary system, tungsten-carbon. A tentative phase diagram is presented which differs significantly from the one proposed by Sykes in 1930 and which is generally accepted today. The data were obtained by high-temperature differential thermal analysis and classical quenching procedures, both supplemented by metallographic, x-ray, and chemical techniques.Results for the tungsten-carbon binary system indicate a eutectic between W and W2C at 2735°C, and a eutectic between W5C3 and C at 2765°C. The W2C lattice accommodates 72 and 74 atomic per cent W at 2475° and 2735°C, respectively. Carbon solubility is evident only at 2540°C, the eutectoid temperature. A new phase, W5C3, was discovered which is stable only above 2540°C. WC decomposes at 2730°C into W5C3 and C.
Provenance: IIT