Transformation enabled nitride magnets absent rare earths and a process of making the same
AssigneeCase Western Reserve University
InventorDavid Matthiesen
Life of this patent
Estimating the term…
Abstract
A process for producing an ordered martensitic iron nitride powder that is suitable for use as a permanent magnetic material is provided. The process includes fabricating an iron alloy powder having a desired composition and uniformity; nitriding the iron alloy powder by contacting the material with a nitrogen source in a fluidized bed reactor to produce a nitride iron powder; transforming the nitride iron powder to a disordered martensitic phase; annealing the disordered martensitic phase to an ordered martensitic phase; and separating the ordered martensitic phase from the iron nitride powder to yield an ordered martensitic iron nitride powder.
Claims15
A material suitable for forming an ordered α″-martensitic iron-based alloy nitride permanent magnet, the material consisting essentially of a single-phase γ-austenite iron-based alloy nitride,
- wherein the single-phase γ-austenite iron-based alloy nitride has a composition consisting essentially of:
- nitrogen in a range from greater than 10.3 at. % to 11.1 at. %;
- an alloy element selected from the group consisting of:
- chromium in a range from 0.9 at. % to 2.7 at. %;
- manganese in a range from 3.1 at. % to 8.7 at. %;
- and
- aluminum in a range from 1.7 at. % to 5.2 at. %;
- and
- a balance of the composition is iron.
A material suitable for forming an ordered α″-martensitic phase iron-based alloy nitride permanent magnet, the material consisting essentially of a single-phase γ-austenite iron-based alloy nitride, wherein the single-phase γ-austenite iron-based alloy nitride has an alloy composition comprising:
- nitrogen in the range from greater than 10.3 at. % to 11.1 at. %;
- and
- an alloying element selected from the group consisting of:
- chromium, aluminum, and manganese;
- wherein the alloying element is included in the alloy composition in an amount that enables the single-phase γ-austenite iron-based alloy nitride to be transformed to the ordered α″-martensitic phase iron-based alloy nitride permanent magnet.
Dependencies are inferred from the claim text.