# US 12,179,266 B2 · 3D printed magnetocaloric devices with controlled microchannels and magnetic anisotropy and methods of making the same

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- Number: US 12,179,266 B2
- Document ID: US12179266B2
- Status: Granted
- Kind: B2
- Application number: 17/319,554
- Filed: 2021-05-13
- Published: 2022-11-17
- Granted: 2024-12-31
- Earliest claimed: 2021-05-13
- Assignees: Virginia Commonwealth University
- Applicants: Virginia Commonwealth University
- Inventors: Hong Zhao; Radhika Barua; Ravi L. Hadimani; Lilly Balderson
- Web page: https://patentgrep.com/patent/US12179266B2

## CPC

- B22F 10/22: Direct deposition of molten metal
- B29C 64/106: using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
- B22F 1/105: containing inorganic lubricating or binding agents, e.g. metal salts
- B22F 1/107: containing organic material comprising solvents, e.g. for slip casting
- B22F 3/10: Sintering only
- B22F 5/10: of articles with cavities or holes, not otherwise provided for in the preceding subgroups
- B22F 7/06: of composite workpieces or articles from parts, e.g. to form tipped tools {(B22F7/002 takes precedence)}
- B22F 10/18: by mixing binder with metal in filament form, e.g. fused filament fabrication [FFF]
- B22F 10/50: Treatment of workpieces or articles during build-up, e.g. treatments applied to fused layers during build-up
- B22F 10/60: Treatment of workpieces or articles after build-up
- B29C 64/188: involving additional operations performed on the added layers, e.g. smoothing, grinding or thickness control (surface shaping B29C59/00; after-treatment of articles without altering their shape B29C71/00)
- B33Y 10/00: Processes of additive manufacturing
- B33Y 40/20: Post-treatment, e.g. curing, coating or polishing
- B33Y 70/00: Materials specially adapted for additive manufacturing
- B33Y 70/10: Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
- B33Y 80/00: Products made by additive manufacturing
- H01F 1/015: {Metals or alloys}
- B22F 3/1021: {Removal of binder or filler (removal of binder from ceramics C04B35/638)}
- B22F 12/55: Two or more means for feeding material
- B22F 2202/05: Use of magnetic field
- B22F 2301/355: Rare Earth - Fe intermetallic alloys
- B22F 2999/00: Aspects linked to processes or compositions used in powder metallurgy
- Y02B 30/00: Energy efficient heating, ventilation or air conditioning [HVAC]
- B22F: WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER (making alloys by powder metallurgy C22C); APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B29C: SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING (making preforms B29B11/00; making laminated products by combining previously unconnected layers which become one product whose layers will remain together B32B37/00 - B32B41/00)
- B33Y: ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
- H01F: MAGNETS; INDUCTANCES; TRANSFORMERS; SELECTION OF MATERIALS FOR THEIR MAGNETIC PROPERTIES
- Y02B: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO BUILDINGS, e.g. HOUSING, HOUSE APPLIANCES OR RELATED END-USER APPLICATIONS

## Abstract

A polymer-assisted 3D printing method and ink compositions are used to manufacture magnetocaloric devices having many applications including in heat pumps, refrigerators, etc. The ink compositions and printing methods can produce compositionally graded, anisotropically aligned magnetocaloric architectures with designed pores and channels, to bring forth significant improvement in heat exchange efficiency.

## Claims

### Claim 1

An ink formulation, comprising:
20-95 wt % solids of magnetocaloric material;
5-80 wt % solids of polymeric binder; and
a plurality of solvents comprising each of
dichloromethane (DCM), ethylene glycol butyl ether (EGBE) and dibutyl phthalate (DBP), 2-butoxyethanol (2-Bu), and polyethylene glycol (PEG), and
wherein the polymeric binder and one or more solvents have a polymer-to-solvent ratio of 0.01 g/mL-0.5 g/mL.

### Claim 2 (depends on 1)

The ink formulation of claim 1 wherein the magnetocaloric material is one or more magnetocaloric powders selected from the group consisting of
FeRh,
Gd5(Si1-xGex)4 where x ranges from 0 to 1,
Co- and H-doped La(Fe13-xSix) where x ranges from 0 to 1,
MnFe(P, As, Si),
AlT2B2 where T is selected from the group consisting of Fe, Mn, Ni, and Co,
MnM′X where M′ is selected from the group consisting of Fe, Co, and Ni, and
where X is selected from the group consisting of Si, Ga, Ge, and Al, and
R1-xMxMnO3, where R is a lanthanide, M is selected from the group consisting of Ca, Sr and Ba, and x ranges from 0 to 1.

### Claim 3 (depends on 1)

The ink formulation of claim 1 wherein the polymeric binder includes one or more polymers selected from the group consisting of polylactic acid (PLA), poly(lactic-co-glycolic) acid (PLGA), polystyrene (PS), and polyethylene oxide (PEO).

### Claim 4 (depends on 1)

The ink formulation of claim 1, further comprising up to 10 wt % thermally conductive additives.

### Claim 5 (depends on 1)

The ink formulation of claim 1, further comprising one or more fillers selected from the group consisting of nanoclay, graphene nanoplatelets, metal nanoparticles, and Ti3(Al,Si)C2.