Accession Number : AD0700589

Title :   PHASE DIAGRAM OF THE NIOBIUM-TIN SYSTEM,

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Svechnikov,V. N. ; Pan,V. M. ; Beletskii,Yu. I.

Report Date : 07 OCT 1969

Pagination or Media Count : 14

Abstract : The phase diagram of the high tin portion of the niobium-tin system was constructed. The temperature range of stability of the various intermetallic compounds was determined. Ten alloys were arc melted, cast, and annealed at 750 degrees centigrade for 700 hr. On the basis of x-ray, thermal and microstructural analysis, a phase diagram was constructed. Differential thermal curves are given, and the various temperature peaks are analyzed. Besides Nb3Sn, two other intermetallic compounds, Nb6Sn5 and NbSn2 exist in the niobium-tin system. However, they only form upon protracted annealing. For case niobium-tin alloys, in which the compounds Nb6 and NbSn2 are absent but in which the above monotectic occurs, a metastable equilibrium diagram can be constructed. In the metastable diagram, the equilibrium monotectic temperature and composition may differ from that obtained for a stable diagram. Apparently, the niobium-tin diagram obtained by Agafonov, et al is a metastable one. (Author)

Descriptors :   (*NIOBIUM ALLOYS, *PHASE DIAGRAMS), (*TIN ALLOYS, PHASE STUDIES), INTERMETALLIC COMPOUNDS, THERMAL STABILITY, EUTECTICS, USSR

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE