JACoW logo

Joint Accelerator Conferences Website

The Joint Accelerator Conferences Website (JACoW) is an international collaboration that publishes the proceedings of accelerator conferences held around the world.


https://doi.org/10.18429/JACoW-SRF2017-TUPB095
Title Modeling the Hydroforming of a Large Grain Niobium Tube With Crystal Plasticity
Authors
  • A. Mapar
    MSU, East Lansing, Michigan, USA
  • T.R. Bielerpresenter
    Michigan State University, East Lansing, Michigan, USA
  • J.E. Murphy
    University of Nevada, Reno, Reno, Nevada, USA
  • F. Pourboghrat
    Ohio State University, Columbus, Ohio, USA
Abstract Current SRF cavities are made from fine grained polycrystalline niobium half-cells welded together. Hot spots are commonly found in the heat-affected zone, making seamless hydroformed cavities attractive. Large grain cavities usually perform as well as fine grain cavities, often having a higher Q, presumably due to fewer grain boundaries. Large grain Nb forms non-uniformly, which introduces problems in manufacturing. A model that could realistically predict the deformation response of large grain Nb could facilitate the design of large grain hydroformed tubes. To this end, a crystal plasticity model was developed and calibrated with tensile stress-strain data of Nb single crystals. A seamless large grain tube was made from rolling a fine grain sheet into a tube, welded, and heat treated to grow large grains. The heat treatment resulted in a large grain tube with a single grain orientation in the center. The tube was hydroformed until it cracked. The hydroforming process was simulated with the crystal plasticity model, which was able to predict the deformed shape of the tube, the location of the crack and other localized areas with heterogeneous strain.
Paper download TUPB095.PDF [1.417 MB / 4 pages]
Export download ※ BibTeX LaTeXText/WordRISEndNote
Conference SRF2017, Lanzhou, China
Series International Conference on RF Superconductivity (18th)
Proceedings Link to full SRF2017 Proccedings
Session Poster Session
Date 18-Jul-17   14:00–17:00
Main Classification SRF Technology R&D
Sub Classification Cavity processing
Keywords ion, cavity, niobium, experiment, SRF
Publisher JACoW, Geneva, Switzerland
Editors Volker RW Schaa (GSI, Darmstadt, Germany); Yuan He (IMP, Lanzhou, China); Lu Li (IMP, Lanzhou, China); Ning Zhao (IHEP, Beijing, China)
ISBN 978-3-95450-191-5
Published January 2018
Copyright
Copyright © 2018 by JACoW, Geneva, Switzerland     CC-BY Creative Commons License
cc Creative Commons Attribution 3.0