Method, apparatus and material mixture for direct digital manufacturing of fiber reinforced parts

Patent metadata

Field	Value
Publication number	US-9457521-B2
Application number	US-201113223924-A
Country	US
Kind code	B2
Filing date	Sep 1, 2011
Priority date	Sep 1, 2011
Publication date	Oct 4, 2016
Grant date	Oct 4, 2016

Abstract

A part is manufactured by introducing magnetic particles into a matrix material, and orienting the particles by coupling them with an electromagnetic field. The matrix material is solidified in patterned layers while the particles remain oriented by the field.

First claim

What is claimed is:

1. A method of manufacturing a part, comprising:
introducing magnetic particles into a powder matrix material, the powder matrix material present in an amount between approximately 50% and 90% by weight, the magnetic particles comprising an elongate synthetic fiber core coated with a magnetic material;
positioning an array of electromagnets proximate the powder matrix material, including aligning the array of electromagnets relative to each other, the array of electromagnets providing an electromagnetic field;
orienting the magnetic particles in the powder matrix material in a unidirectional alignment by coupling the particles with the electromagnetic field provided by the array of electromagnets;
altering the electromagnetic field to move the magnetic particles toward a layer of the part; and
curing the powder matrix material with a directed energy beam while the magnetic particles are oriented.

2. The method of claim 1 , further comprising:
moving a head relative to a vat including the magnetic particles and the matrix material, the array of electromagnets positioned in the head;
using the array of electromagnets to generate the electromagnetic field and accumulate the magnetic particles on a surface of the part; and
directing an energy beam from the head to solidify the powder matrix material so as to form the continuous outer metallic layer on the surface of the part, the layer being conductive.

3. The method of claim 2 , wherein accumulating the magnetic particles includes aligning the magnetic particles in both an end-to-end and side-by-side continuous alignment along the surface of the part.

4. The method of claim 1 , further comprising:
using the electromagnetic field to form a feature of the part by repositioning the magnetic particles, the feature including a layer of conductive material formed from the magnetic particles.

5. The method of claim 1 , wherein each elongate synthetic fiber core further comprises:
a plurality of aligned synthetic fibers.

6. The method of claim 1 , wherein:
the curing is performed by sintering the powder matrix material.

7. The method of claim 1 , wherein the magnetic particles include at least one of aramid, glass, and carbon fibers having a magnetic coating.

8. The method of claim 1 , wherein the matrix material is one of:
a polymeric powder; and
a metal powder.

9. The method of claim 1 , wherein the magnetic particles comprise chopped fibers having a length between approximately 3 and 6 mm.

10. The method of claim 1 , wherein the magnetic particles comprise milled fibers having a length between approximately 50 and 500 microns.

11. The method of claim 1 , further comprising:
moving a number of magnetic particles to a surface in the part; and
forming a conductive layer at the surface.

12. A method of manufacturing a fiber reinforced composite part, comprising:
suspending magnetic reinforcing fibers in a liquid resin, the magnetic reinforcing fibers comprising a fiber core coated with a magnetic material, the liquid resin present in an amount between approximately 50% and 90% by weight;
generating an electromagnetic field;
using the electromagnetic field to orient the fibers within the liquid resin in a unidirectional alignment;
altering the electromagnetic field to move the magnetic reinforcing fibers to create a layer in the composite part; and
moving an energy beam and the electromagnetic field over the liquid resin to cure the resin in a pattern within the layer so as to form a continuous conductive layer of the composite part.

13. The method of claim 12 , wherein generating the electromagnetic field is performed using at least two aligned electromagnets positioned in a head, the energy beam also directed from the head.

14. The method of claim 12 , wherein the fibers include a substantially non-magnetic material surrounded by a magnetic material, the substantially nonmagnetic material comprising one of aramid, glass, and carbon fibers.

15. The method of claim 12 , wherein using an energy beam to cure to the liquid resin is performed using a computer controlled ultraviolet laser to scan the layer and to selectively cure portions of the layer.

16. The method of claim 12 , wherein the layer comprises a conductive surface of the part.

17. A direct digital manufacturing method for producing a part, comprising:
using an energy field to align elongate reinforcing fibers in a matrix material, wherein elongate reinforcing fibers exhibiting magnetic properties and the matrix material are present in an amount between approximately 50% and 90% by weight;
using the energy field to orient the reinforcing fibers within the liquid resin in a unidirectional alignment;
altering the energy field to move the reinforcing fibers to create a layer in the composite part;
moving a digitally controlled energy beam and the energy field over the mixture to cure the matrix material so as to form a continuous conductive layer of the part; and
using the digitally controlled energy beam to selectively solidify portions of the matrix material, layer-by-layer, based on a digital definition of the part.

18. The method of claim 17 , wherein using an energy field to align the fibers is performed using electromagnets positioned on a gantry and configured to rotate.

19. The method of claim 17 , wherein:
the matrix material is a powder, and
solidifying the matrix material is performed by sintering the powder.

20. The method of claim 17 , wherein:
the matrix material liquid polymer resin, and
the fibers are suspended in the liquid resin.

Assignees

• Johnston Scott Robert
• Vance Jonathan Blake
• Fonda James William
• Lyons Brett Ian
• Boeing Co

Inventors

• Johnston Scott Robert
• Vance Jonathan Blake
• Fonda James William
• Lyons Brett Ian

Classifications

• B29C64/188

  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) · CPC title

• B22F10/20

  Direct sintering or melting · CPC title

• B22F10/38

  to achieve specific product aspects, e.g. surface smoothness, density, porosity or hollow structures · CPC title

• C22C47/025

  Aligning or orienting the fibres · CPC title

• B29C70/88 Primary

  characterised primarily by possessing specific properties, e.g. electrically conductive or locally reinforced · CPC title