Accession Number : AD0476624

Title :   TERNARY PHASE EQUILIBRIA IN TRANSITION METAL-BORON-CARBON-SILICON SYSTEMS. PART II. TERNARY SYSTEMS. VOLUME III. ZR-TA-C SYSTEM.

Descriptive Note : Technical rept.,

Corporate Author : AEROJET-GENERAL CORP SACRAMENTO CA MATERIALS RESEARCH LAB

Personal Author(s) : Harmon, D. P. ; Brukl, C. E.

Report Date : NOV 1965

Pagination or Media Count : 72

Abstract : The ternary zirconium-tantalum- carbon system was investigated using X-ray, DTA, melting point, and metallographic techniques on chemically analyzed alloys; a complete phase diagram for temperatures above 1000 C was established. The system contains a high melting continuous solid solution of binary monocarbide phases; a moderate zirconium-tantalum exchange occurs in both the high and low temperature modifications of the subcarbide, Ta2C. Two four-phase reaction planes and two limiting tie-lines are present in the metal-rich portion of the ternary diagram. A minimum melting point occurs in the zirconium-rich portion of the ternary. The results of this investigation are described and discussed; selection of alloys for general high temperature applications is discussed in the light of the results of the Zr-Ta-C investigation. A brief thermodynamical evaluation of the system is given along with a calculated isothermal section at 1500 C. (Author)

Descriptors :   , , (*TRANSITION METALS, ALLOYS), (*REFRACTORY METAL ALLOYS, PHASE STUDIES), ZIRCONIUM ALLOYS, TANTALUM ALLOYS, CARBIDES, X RAY DIFFRACTION, MELTING POINT, METALLOGRAPHY, SOLID SOLUTIONS, CRYSTAL STRUCTURE, CRYSTAL LATTICES, EUTECTICS, HYDRIDES, ZIRCONIUM COMPOUNDS, HIGH TEMPERATURE, TRANSITION TEMPERATURE.

Subject Categories : Properties of Metals and Alloys
      Thermodynamics

Distribution Statement : APPROVED FOR PUBLIC RELEASE