High-entropy alloys (HEAs), methods for making HEAs, and uses thereof
AssigneeThe United States of America as represented by the Secretary of the Navy
InventorsSuok-Min Na, Paul K. Lambert, Nicholas J. Jones
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Abstract
High entropy alloys (HEAs) are provided, which exhibit a high magnetic entropy change over a large temperature range, as well as methods for making HEAs. The invention also provides HEAs that exhibit notable magnetostriction at room temperature, and alloying methods for producing them. The materials and methods of the invention may be used, for example, in solid-state refrigeration apparatus and methods, as well as in transduction devices and energy harvesting applications.
Claims9
An alloy comprising:
- Fe from 15 at % to 20 at %, Co from 15 at % to 20 at %, Ni from 15 at % to 30 at %, Cr from 10 at % to 20 at %, Mn from 15 at % to 20 at %, and Ga from 15 at % to 30 at %,
- wherein a base alloy composition comprises FeCoNiCr,
- wherein an alloying addition is MnGa,
- wherein the alloying addition provides the alloy with a polycrystalline magnetostriction property of at least 3 ppm across a range of temperatures, the range of temperatures spanning a room temperature and a cryogenic temperature, and
- wherein the alloy is subject to an annealing process that changes h a-e polycrystalline magnetostriction property across the range of temperatures relative to an as-cast alloy polycrystalline magnetostriction property, and
- wherein the room temperature is 300 K and the cryogenic temperature is 78 K.
A solid-state refrigeration apparatus, comprising:
- an alloy comprising:
- Fe from 15 at % to 20 at %, Co from 15 at % to 20 at %, Ni from 15 at % to 30 at %, Cr from 10 at % to 20 at %, Mn from 15 at % to 20 at %, and Ga from 15 at % to 30 at %,
- wherein a base alloy composition comprises FeCoNiCr,
- wherein an alloying addition is MnGa,
- wherein the alloying addition provides the alloy with a polycrystalline magnetostriction property of at least 3 ppm across a range of temperatures, the range of temperatures spanning a room temperature and a cryogenic temperature, and
- wherein the alloy is subject to an annealing process that changes h polycrystalline magnetostriction property across the range of temperatures relative to an as-cast alloy polycrystalline magnetostriction property, and
- wherein the room temperature is 300 K and the cryogenic temperature is 78 K;
- and
- a source of magnetic field.
An alloy comprising:
- Fe from 15 at % to 20 at %, Co from 15 at % to 20 at %, Ni from 15 at % to 30 at %, Cr from 10 at % to 20 at %, Mn from 15 at % to 20 at %, and Ga from 15 at % to 30 at %,
- wherein a base alloy composition comprises FeCoNiCr,
- wherein an alloying addition is MnGa,
- wherein the alloy is subject to an annealing process that changes a polycrystalline magnetostriction property of the alloy.
Dependencies are inferred from the claim text.