Accession Number : AD0480801

Title :   TERNARY PHASE EQUILIBRIA IN TRANSITION METAL-BORON-CARBON-SILICON SYSTEMS. PART II. TERNARY SYSTEMS. VOLUME IV. THE TI-ZR-C, TI-HF-C, AND ZR-HF-C SYSTEMS.

Descriptive Note : Technical rept.,

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

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

Report Date : JAN 1966

Pagination or Media Count : 78

Abstract : Solid-state sections of the ternary Ti-Zr-C and Ti-Hf-C systems were investigated; the complete Zr-Hf-C system was studied from 1600 C to melting using X-ray, DTA, melting point, and metallographic techniques on chemically analyzed alloys; a complete phase diagram for the Zr-Hf-C system for temperatures above 1600 C was established. The hafnium metal used contained 4 At.% zirconium. The Ti-Zr-C system contains a miscibility gap in the monocarbide region; the miscibility gap is completely closed at temperatures above approximately 2150 C. A miscibility gap is also present in the Ti-Hf-C system in the monocarbide region; complete solid solubility exists between the binary monocarbides at temperatures above approximately 2050 C. The Zr-Hf-C system contains a high melting, continuous monocarbide solid-solution in a carbon defect lattice. The a-hafnium phase is stabilized toward higher temperatures by carbon; this phase shows a moderate solubility for carbon and zirconium. One four-phase reaction plane is present in the metal-rich portion of the ternary diagram. The results of these investigations are described and discussed; application possibilities are briefly mentioned. (Author)

Descriptors :   , (*TRANSITION METALS, HIGH TEMPERATURE), (*REFRACTORY METALS, PHASE STUDIES), TITANIUM, CARBIDES, BORON, SILICON, ZIRCONIUM, HAFNIUM, MELTING POINT, STABILITY, METALLOGRAPHY, HEAT TREATMENT, CHEMICAL ANALYSIS, X RAY DIFFRACTION, DIFFERENTIAL THERMAL ANALYSIS, HYDRIDES, POWDER METALS.

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE