Intermediate Phases in Superconducting Niobium-Tin Alloys
260 ## - PUBLICATION, DISTRIBUTION, ETC.
Name of publisher, distributor, etc.
[Gaithersburg, MD] : U.S. Dept. of Commerce, National Institute of Standards and Technology,
Date of publication, distribution, etc.
1962.
500 ## - GENERAL NOTE
General note
/pmc/articles/PMC5312820/
520 ## - SUMMARY, ETC.
Summary, etc.
In attempting to produce superconducting wire of the niobium sheath Nb(3)Sn core type, it became apparent that results were generally unpredictable. Metallographic examination showed that such materials are heterogeneous and contain a number of intermediate phases. Detailed metallographic studies were made on diffusion zones in which tin had been allowed to react with porous niobium blocks, with fused niobium rod, and with niobium wires, and on a number of reacted powder mixtures. The phases produced were identified by anodizing to characteristic colors and by microspot analysis, supplemented by some hot-stage microscope and thermal analysis tests. On the basis of these observations, a tentative revised diagram is offered to illustrate the types of reactions which occur in the system. The presumably desired phase, Nb(3)Sn, is found to lie between the more easily formed phases Nb(4)Sn and Nb(2)Sn(3), which are stable to temperatures well above the peritectoid decomposition of the Nb(3)Sn. At lower temperatures the compound Nb(2)Sn is formed. It is indicated that the high-temperature treatment to react niobium and tin should be followed either by very slow cooling or by an anneal in the 600 to 700 °C range to form Nb(3)Sn.
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Terms governing use and reproduction
540 ## - TERMS GOVERNING USE AND REPRODUCTION NOTE
540 ## - TERMS GOVERNING USE AND REPRODUCTION NOTE
Terms governing use and reproduction
The Journal of Research of the National Bureau of Standards Section A is a publication of the U.S. Government. The papers are in the public domain and are not subject to copyright in the United States. Articles from J Res may contain photographs or illustrations copyrighted by other commercial organizations or individuals that may not be used without obtaining prior approval from the holder of the copyright.
546 ## - LANGUAGE NOTE
Language note
en
690 ## - LOCAL SUBJECT ADDED ENTRY--TOPICAL TERM (OCLC, RLIN)
