RESEARCH STUDY TO DETERMINE THE PHASE EQUILIBRIUM RELATIONS OF SELECTED METAL CARBIDES AT HIGH TEMPERATURES
Abstract
INVESTIGATIONS WERE MADE OF PHASE EQUILIBRIA IN THE BINARY SYSTEMS, W-C and Zr-C. A completed phase diagram for the W-C system is presented which differs significantly from the one proposed by Sykes (Trans. Am. Soc. Steel Treating 18:968, 1930) and which is generally accepted today. A tentative phase diagram for the Zr-C system i included. Data were obtained by hightemperature differential thermal analysis and classical quenching procedures, both supplemented by metallographic, X-ray, and chemical techniques. Resulbetween W and W2C at 2710 C and between W2C and beta-WC at 2765 C. The W2C lattice accommodates 7 and 74 at-% W at 2460 nd 2710 C, respectively. Carbon solubility is evident only a 2525 C, the eutectoid temperature. The melting point of W2C was found to be 2795 C. At 2755 C, WC decomposes into beta-WC and graphite. A new cubic phase (beta-WC) has been discovered which is stable only above 2525 s for the W-C binary system indicate eutectics between W and W2C at 2710 C and between W2C and beta-WC at 2765 C. The W2C lattice accommodates 7 and 74 at-% W at 2460 nd 2710 C, respectively. Carbon solubility is evident only a 2525 C, the eutectoid temperature. The melting point of W2C was found to be 2795 C. At 2755 C, WC decomposes into beta-WC and graphite. A new cubic phase (beta-WC) has been discovered which is stable only above 2525 C. The Zr-C system is characterized by eutectic temperatures of 1860 and 2850 C on the Zr-rich and C-rich sides of ZrC, respectively. ZrC is the only carbide phase which has been observed in this syst m. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1962
- Accession Number
- AD0277794
Entities
People
- R.t. Dolloff
- R.v. Sara