Process and materials for printed magnets

Patent metadata

Field	Value
Publication number	US-2019252099-A1
Application number	US-201815894210-A
Country	US
Kind code	A1
Filing date	Feb 12, 2018
Priority date	Feb 12, 2018
Publication date	Aug 15, 2019
Grant date	—

Abstract

A composite magnetic material includes magnetic particles with a first shape and a volume fraction. The composite material also includes a polymeric matrix surrounding the particles and has fractional remanence greater than 0.5. In an embodiment, a dispersion of magnetic particles in a continuous curable polymer matrix includes a particle volume fraction of greater than 60% and a fractional remanence of 0.5 or higher.

First claim

1 . A composite magnetic material formed by additive manufacturing comprising:
magnetic particles with a shape, volume fraction, particle size and particle size distribution; a polymeric matrix surrounding the magnetic particles; and fractional remanence greater than 0.5.

2 . The material of claim 1 , wherein the volume fraction is greater than 60%.

3 . The material of claim 1 , further comprising a fractional coercivity that is greater than 0.95.

4 . The material of claim 1 , wherein the magnetic particles comprise NdFeB, rare earth cobalt, strontium ferrite, Alnico (Fe—Al—Ni—Co—Cu Ti) alloys, or mixtures thereof.

5 . The material of claim 1 , wherein the polymeric matrix comprises a material selected from the group consisting of methacrylate, silicone, epoxy resins, and mixtures thereof.

6 . The material of claim 1 wherein the shape of the magnetic particles comprises a sphere, spheroid, rod, fiber, plate, disk, prismatic, or mixtures thereof.

7 . The material of claim 6 , wherein the shape of the magnetic particles comprises a sphere.

8 . The material of claim 1 , wherein the additive manufacturing comprises injection molding, fused deposition modeling, selective laser sintering, binder jet, direct write, direct write with near UV cure or mixtures thereof.

9 . The material of claim 8 , wherein the additive manufacturing comprises direct write with near UV cure.

10 . The material of claim 1 wherein the particle size distribution is multimodal.

11 . The material of claim 1 wherein the particle size is from about 0.01 micron to about 500 microns.

12 . A dispersion of magnetic particles in a continuous curable polymer matrix comprising:
a particle volume fraction of greater than 60%; and a fractional remanence of 0.5 or higher.

13 . The dispersion of claim 12 , further comprising a fractional coercivity of greater than 0.95.

14 . The dispersion of claim 12 , wherein the magnetic material comprises NdFeB, rare earth cobalt, strontium ferrite, Alnico, (Fe—Al—Ni—Co—Cu—Ti) alloys, or mixtures thereof.

15 . The dispersion of claim 12 , wherein the shape of the magnetic particles comprises a sphere, spheroid, rod, fiber, plate, disk, prismatic, or mixtures thereof.

16 . The dispersion of claim 15 , wherein the shape of the magnetic particles is spherical.

17 . The dispersion of claim 12 , wherein the continually curable polymer matrix is selected from the group consisting of methacrylate, silicone, epoxy resins, and mixtures thereof.

18 . The dispersion of claim 12 , wherein the magnetic particle size distribution in the dispersion is multimodal.

19 . The dispersion of claim 18 , wherein the magnetic particle size distribution in the dispersion is bimodal.

20 . The dispersion of claim 12 , wherein the magnetic particle size in the dispersion from about 0.01 micron to about 500 microns.

Assignees

• United Technologies Corp

Inventors

• Dardona Sameh
• Bailey Callum

Classifications

• H01F1/0571 Primary

  in the form of particles, e.g. rapid quenched powders or ribbon flakes · CPC title

• B33Y80/00 Primary

  Products made by additive manufacturing · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• H01F1/11

  in the form of particles {(for magnetic record carriers G11B5/70626)} · CPC title

• H01F1/047

  Alloys characterised by their composition · CPC title