MSE Seminar: Xingchen Xu, Toward controlling grain size and composition of Nb3Sn superconductors

Ph.D. Candidate advised by Dr. Michael Sumption

All dates for this event occur in the past.

184 Watts Hall
2041 College Rd
Columbus, OH 43210
United States

Abstract

Superconducting Nb3Sn strands have significant application prospects due to their capability to carry high loss-less currents. Such strands are composed of Cu-Sn and Nb precursors in the green state; the precursors transform to Nb3Sn phase through a diffusion reaction process during a heat treatment at 600-700 °C. The current-carrying capability of Nb3Sn can be significantly improved by grain size refinement. In this work, the internal oxidation method is introduced to Nb3Sn strands, in which Nb-Zr alloy is internally oxidized to form fine ZrO2 precipitates in the Nb3Sn layer, which remarkably refine Nb3Sn grain size. In addition, Nb3Sn compound has a composition range (17 - 26 at.% Sn), and its current-carrying capability at high magnetic fields drops dramatically as its Sn content decreases. In this work we try to develop a model to find out what controls the Sn content of the Nb3Sn phase formed in the diffusion reaction process.

Bio

Xingchen Xu comes from China. He received his bachelor’s degree in Materials Forming Engineering from Harbin Institute of Technology. He began his PhD study on Nb3Sn superconductor at OSU in 2011.