Accession Number : AD0637375

Title :   SYSTEM NIOBIUM - TUNGSTEN - MOLYBDENUM AIRCONIUM.

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Savitskii,E. M. ; Zakharov,A. M.

Report Date : 22 APR 1966

Pagination or Media Count : 16

Abstract : By microscopic methods, the determination of the melting point, microphardness, and X-ray methods the structure of six primary sections of the tetrahedron niobium - tungstenmolybdenum -zirconium, parallel to the edge of the ternary system tungsten - molybdenum - zicronium, and also a number of secondary sections were studied; the investigated alloys contained totals of 5; 7.5; 10; 15; 20; and 30 wt.% of tunngsten, molybdenum and zirconium, the remainder being niobium. Projections were constructed of the surfaces of the solidus curve and also the isotherm of cited primary sections at temperatures of 2000, 1800, 1500, and 1100C. The investigated alloys had a single-phase or two-phase structure; single-phase alloys constituted quaternary solid solutions of tungsten, molybdenum, and zirconium in niobium, and in the structure of the two-phase alloys there were also observed cystals of the excess phase (W, Mo)2Zr. A three-dimensional projection of the quaternary system niobium - tungsten - molybdenum - zirconium was consturcted in the form of a polythermic tetrahedron, making it possible to explain the processes of crystallization of the various alloys and their structure in the solid state. (Author)

Descriptors :   (*PHASE STUDIES, TRANSITION METALS), (*NIOBIUM ALLOYS, PHASE STUDIES), (*TUNGSTEN ALLOYS, PHASE STUDIES), (*MOLYBDENUM ALLOYS, PHASE STUDIES), (*ZIRCONIUM ALLOYS, PHASE STUDIES), TRANSITION TEMPERATURE, MICROSTRUCTURE, USSR, MELTING, HARDNESS

Subject Categories : Physical Chemistry
      Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE