Abstract: A new heat treatment for Internal-Tin Nb3Sn strands is described. The heat treatment uses Nausite membranes to decrease the volume fraction of the ? phase and therefore minimize its liquefaction—ultimately resulting in better connected Nb3Sn. The heat treatment requires only one stage aside from the final Nb3Sn reaction stage. This heat treatment enables an increase in critical current density (at 16 T) of 28%.
Type:
Grant
Filed:
January 24, 2018
Date of Patent:
November 3, 2020
Assignee:
Bruker OST LLC
Inventors:
Michael Field, Hanping Miao, Carlos Sanabria, Jeffrey Parrell
Abstract: Methods for producing a multifilament Nb3Sn superconducting wire having a Jc value of at least 2000 A/mm2 at 4.2 K and 12 T by a) packing a plurality of Cu encased Nb rods within a first matrix which is surrounded by an intervening Nb diffusion barrier and a second matrix on the other side of the barrier remote from the rods thereby forming a packed subelement for the superconducting wire; b) providing a source of Sn within the subelement; c) assembling the metals within the subelement, the relative sizes and ratios of Nb, Cu and Sn being selected such that (i) the Nb fraction of the subelement cross section including and within the diffusion barrier is from 50 to 65% by area; (ii) the atomic ratio of the Nb to Sn including and within the diffusion barrier of the subelement is from 2.7 to 3.7; (iii) the ratio of the Sn to Cu within the diffusion barrier of the subelement is such that the Sn wt %/(Sn wt %+Cu wt %) is 45%-65%; (iv) the Cu to Nb local area ratio (LAR) of the Cu-encased Nb rods is from 0.10 to 0.
Type:
Grant
Filed:
January 25, 2017
Date of Patent:
February 25, 2020
Assignee:
Bruker OST LLC
Inventors:
Michael Field, Hanping Miao, Carlos Sanabria, Jeffrey Parrell
Abstract: A new heat treatment for Internal-Tin Nb3Sn strands is described. The heat treatment uses Nausite membranes to decrease the volume fraction of the ? phase and therefore minimize its liquefaction—ultimately resulting in better connected Nb3Sn. The heat treatment requires only one stage aside from the final Nb3Sn reaction stage. This heat treatment enables an increase in critical current density (at 16 T) of 28%.
Type:
Application
Filed:
January 24, 2018
Publication date:
July 26, 2018
Applicant:
Bruker OST LLC
Inventors:
Michael Field, Hanping Miao, Carlos Sanabria, Jeffrey Parrell