Quantification of Second Phase Morphology in SSCL VQP Samples

  • J. M. Seuntjens
  • F. Y. Clark
  • T. J. Headley
  • A. C. Kilgo
  • N. Y. C. Yang
Part of the An International Cryogenic Materials Conference Publication book series (ACRE, volume 40)

Abstract

Select heat treatment and final size strand sample sets from Phase I of the VQP have been microstructurally characterized by electron microscopy. Samples taken after each of the precipitation heat treatments had their α-Ti second phase precipitate size and volume fraction analyzed by backscattered electron imaging (BEI) in both Transmission Electron Microscopy (TEM) and Field Emission Scanning Electron Microscopy (FESEM), both coupled with image analysis techniques. Final size strand microstructure was imaged by bright field TEM. The α-Ti “ribbon” thickness and spacing were determined by a line intercept analysis. Procedures used for sample preparation, image acquisition, and image analysis, are presented. The post heat treatment second phase volume fraction was found to vary on a size scale of a few microns. As a result, the calculated volume fraction from different images from the same NbTi filament can have significant variations. FESEM has much easier sample preparation than TEM and FESEM images are not complicated by thickness effects or precipitate “ghost” images from precipitates within the thickness of the foil. Results indicate that the post final heat treatment mean precipitate diameter, as well as the final size α-Ti ribbon thickness, is similar for all VQP vendors and independent of NbTi alloy source.

Keywords

Field Emission Scan Electron Microscopy Final Size Backscatter Electron Imaging Transmission Electron Microscopy Sample Ribbon Thickness 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. 1).
    Adobe Photoshop,Adobe Systems, Inc., 1585 Charleston Road, P.O. box 7900, Mountain View, CA 94039–7900, (1991).Google Scholar
  2. 2).
    Image Analyst,Automatix Inc., 755 Middlesex Tumpike, Billerica, MA 01821, (1991).Google Scholar
  3. 3).
    J. M. Seuntjens, F. Y. Clark, T. J. Headley, F. A. Greulich, and N. Y. C. Yang, Image Analysis of SSC Strand,IEEE Trans. on Appl. Superconductivity 3 pp. 729–733, (1993).Google Scholar
  4. 4).
    J. M. Seuntjens, F. Y. Clark, M. J. Erdmann, E. S. Coleman, and B. A. Jones, Comparisons of Processes and Performance of SSC-VQP Material, to appear in Supercollider 5 (1993).Google Scholar

Copyright information

© Springer Science+Business Media New York 1994

Authors and Affiliations

  • J. M. Seuntjens
    • 1
  • F. Y. Clark
    • 1
  • T. J. Headley
    • 2
  • A. C. Kilgo
    • 2
  • N. Y. C. Yang
    • 3
  1. 1.Superconducting Supercollider LaboratoryDallasUSA
  2. 2.Sandia National LaboratoriesAlbuquerqueUSA
  3. 3.Sandia National LaboratoriesLivermoreUSA

Personalised recommendations