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Title: Method of making iron nitride powder with anisotropic shape

Patent ·
OSTI ID:1632557

Techniques are disclosed for milling an iron-containing raw material in the presence of a nitrogen source to generate anisotropically shaped particles that include iron nitride and have an aspect ratio of at least 1.4. Techniques for nitridizing an anisotropic particle including iron, and annealing an anisotropic particle including iron nitride to form at least one a″-Fe16N2 phase domain within the anisotropic particle including iron nitride also are disclosed. In addition, techniques for aligning and joining anisotropic particles to form a bulk material including iron nitride, such as a bulk permanent magnet including at least one a″-Fe16N2 phase domain, are described. Milling apparatuses utilizing elongated bars, an electric field, and a magnetic field also are disclosed.

Research Organization:
Univ. of Minnesota, Minneapolis, MN (United States)
Sponsoring Organization:
USDOE Advanced Research Projects Agency - Energy (ARPA-E)
DOE Contract Number:
AR0000199
Assignee:
Regents of the University of Minnesota (Minneapolis, MN)
Patent Number(s):
10,562,103
Application Number:
15/546,359
OSTI ID:
1632557
Resource Relation:
Patent File Date: 01/22/2016
Country of Publication:
United States
Language:
English

References (7)

Iron Nitride Materials and Magnets Including Iron Nitride Materials patent-application May 2016
Iron nitride magnetic powder and method of producing the powder patent-application September 2005
Method for producing iron-nitride powders patent July 1994
Transformation Enabled Nitride Magnets Absent Rare Earths and a Process of Making the Same patent-application October 2014
Influence of milling temperature and atmosphere on the synthesis of iron nitrides by ball milling journal February 1996
Method to Synthesize Bulk Iron Nitride patent-application July 2016
Field-ball milling induced anisotropy in magnetic particles journal December 2004