RESEARCH STUDY TO DETERMINE THE PHASE EQUILIBRIUM RELATIONS OF SELECTED METAL CARBIDES AT HIGH TEMPERATURES
Abstract
This report is the result of investigations of phase equilibria in the binary systems, zirconium-carbon, tantalum-carbon, and boron-carbon. A completed phase diagram which encompasses experimental results and considerations heretofore unreported in the literature, is presented for the zirconium-carbon system. A tentative phase diagram for the tantalum-carbon system is included, which, in general, resembles the version released by Ellinger in 1943. Preliminary results for the boron-carbon system, depicting maximum solubility in the graphite lattice below the eutectic temperature of approximately 2390 C, are also included. The zirconium-carbon system is characterized by eutectic temperatures of 1850 and 2850 C on the zirconium-rich and carbon rich sides of ZrC, respectively. The tantalum carbon system is characterized by two high temperature phases, TaC and Ta2C. A eutectic is observed at 2825 C between Ta and Ta2C. Below the B4C-C eutectic temperature of 2390 C, maximum boron solubilities in graphite are found to be 1.50, 2.25, and 2.75 atomic per cent at temperatures of 2000, 2200, and 2350 C, respectively.
Document Details
- Document Type
- Technical Report
- Publication Date
- Feb 01, 1963
- Accession Number
- AD0402797
Entities
People
- C. E. Lowell
- R. T. Dolloff
- R. V. Sara