Accession Number : AD0803913

Title :   TERNARY PHASE EQUILIBRIUM IN TRANSITION METAL-BORON-CARBON-SILICON SYSTEMS. PART II. TERNARY SYSTEMS. VOLUME XII. TI-ZR-B SYSTEM. INVESTIGATION OF PSEUDO-BINARY SYSTEMS ZRB2-NBB2, ZRB2-TAB2, AND HFB2-NBN2.

Descriptive Note : Technical rept.,

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

Personal Author(s) : Eckert, T. E.

Report Date : JAN 1967

Pagination or Media Count : 47

Abstract : The ternary system titanium-zirconium-boron was investigated from 1000 C to 3245 C, the melting temperature of zirconium diboride. The equilibria which exist have been determined except for the boron-rich equilibria which have been estimated. The following notable features were found: minimum melting occurs in the titanium rich corner of the ternary; a four-phase reaction involving beta-metal phase, monoboride, diboride, and liquid occurs at a temperature slightly higher than the minimum melting; zirconium exchanges with titanium in titanium monoboride to about 9 At.% zirconium; and the metal diborides form a continuous series of solid solutions. No ternary compounds were found. The techniques used in the investigation were X-ray analysis, melting point determination, and metallographic examination. Lattice parameter plots of the pseudo-binary systems ZrB2-NbB2, ZrB2-TaB2, and HfB2-NbB2 indicate that in each of these systems the diborides form a continuous series of solid solutions. Melting point temperatures for these systems have been determined. (Author)

Descriptors :   *BORIDES), (*ZIRCONIUM ALLOYS, (*TITANIUM ALLOYS, BORIDES), (*PHASE STUDIES, TRANSITION METALS), CORROSION RESISTANCE, POWDER METALS, HIGH TEMPERATURE, MELTING POINT, IMPURITIES, ARC MELTING, HEAT TREATMENT, METALLOGRAPHY, X RAYS, THERMAL SHOCK, HARDNESS, MICROSTRUCTURE.

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE