Accession Number : AD0671550

Title :   TERNARY PHASE EQUILIBRIA IN TRANSITION METAL-BORON-CARBON-SILICON SYSTEMS. PART I. BINARY SYSTEMS. VOLUME XIII. THE ZIRCONIUM-SILICON AND HAFNIUM-SILICON SYSTEMS.

Descriptive Note : Documentary rept.,

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

Personal Author(s) : Brukl,C. E.

Report Date : MAY 1968

Pagination or Media Count : 72

Abstract : The zirconium-silicon and hafnium-silicon binary systems were investigated by means of Debye-Scherrer X-ray analysis, metallography, melting points, differential analysis techniques, and chemical analysis. Both silicide systems contain a D8(8)-type phase which is stabilized by trace impurities of oxygen and nitrogen. The binary phases present are: Zr4Si, Zr2Si, Zr3Si2, Zr5Si4, alpha- and Beta-ZrSi, and ZrSi2; in the hafnium system: Hf2Si, Hf3Si2, Hf5Si4, and HfSi2. The ZrSi phase undergoes an allotropic transformation at 1550C; the high temperature form is of the CrB type while the low temperature crystal structure is of the FeB type. Complete phase diagrams from 1100C up to melting are given. (Author)

Descriptors :   (*REFRACTORY MATERIALS, PHASE STUDIES), (*ZIRCONIUM ALLOYS, PHASE STUDIES), (*HAFNIUM ALLOYS, PHASE STUDIES), (*SILICON ALLOYS, PHASE STUDIES), X RAY DIFFRACTION, METALLOGRAPHY, MELTING POINT, DIFFERENTIAL THERMAL ANALYSIS, CHEMICAL ANALYSIS, TRANSFORMATIONS, CRYSTAL STRUCTURE, PHASE DIAGRAMS, REFRACTORY METAL ALLOYS

Subject Categories : Ceramics, Refractories and Glass
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE