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Title: Development of rare earth regenerator materials in fine wire form

The use of rare earth metals, both in the pure and alloyed state, have been examined for use as regenerators in cryocooler applications and as the working material in active magnetic refrigerators. In both applications there is a requirement for the rare earth material to have a constant and uniform cross section, an average size on the order of 50-200 microns in diameter, and low levels of impurities. Existing powder production methods have drawbacks such as oxygen contamination, non-uniform size, inconsistent cross sections, and low production yields. A novel approach for the production of rare earth metals and alloys in fine wire form has been developed. This is accomplished by assembling a copperjacket and niobium barrier around a RE ingot, extruding the assembly, and reducing it with standard wire drawing practices. Strand anneals are utilized between drawing passes when necessary in order to recrystallize the RE core and restore ductility. The copperjacket is removed by chemical means at final size, leaving the Nb barrier in place as a protective coating. This process has been applied to gadolinium, dysprosium and a GdDy alloy.
Authors:
;  [1]
  1. Supercon, Inc., Shrewbury, MA (United States)
Publication Date:
OSTI Identifier:
477554
Report Number(s):
CONF-950722-
Journal ID: ACYEAC; ISSN 0065-2482; TRN: 97:009225
Resource Type:
Journal Article
Resource Relation:
Journal Name: Advances in Cryogenic Engineering; Journal Volume: 42A; Conference: CEC/ICMC `95: cryogenic engineering conference and international cryogenic materials conference, Columbus, OH (United States), 17-21 Jul 1995; Other Information: PBD: 1997
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; 66 PHYSICS; MAGNETIC REFRIGERATORS; GADOLINIUM BASE ALLOYS; DRAWING; DYSPROSIUM ALLOYS; DYSPROSIUM; GADOLINIUM; WIRES; MAGNETIC MATERIALS