Powder spreading in binder jetting for additive manufacturing

Patent metadata

Field	Value
Publication number	US-2018304367-A1
Application number	US-201815959111-A
Country	US
Kind code	A1
Filing date	Apr 20, 2018
Priority date	Apr 21, 2017
Publication date	Oct 25, 2018
Grant date	—

Abstract

The devices, systems, and methods of the present disclosure are directed to spreading powder to facilitate accurate layer-by-layer fabrication of three-dimensional objects formed through binder jetting. More specifically, a spreader may be moved across a volume defined by a powder box to spread the powder in a layer. As the spreader is moved across the volume, the spreader may vibrate to pack the powder in the volume. By applying this vibration to the powder on a layer-by-layer basis, the resulting three-dimensional object formed through the binder jetting process may have improved density. In turn, such improved density may be useful for forming the three-dimensional objects into finished parts meeting target density standards, which may be particularly useful in the fabrication of metal parts. Further, or instead, applying vibration to the powder may reduce the likelihood of layer-to-layer variations in the three-dimensional object, thus reducing the likelihood of defects in finished parts.

First claim

What is claimed is:

1 . An additive manufacturing method, the method comprising:
moving at least one roller across a volume defined by a powder box, movement of the at least one roller across the volume spreading a layer of a powder across the volume; as the at least one roller spreads the layer across the volume, vibrating the at least one roller to pack the powder in the volume; and delivering a binder from a print carriage to the layer of the powder in a predetermined two-dimensional pattern associated with the layer as the print carriage moves over the volume.

2 . The method of claim 1 , wherein moving the at least one roller across the volume includes rotating the at least one roller in a direction counter to a direction of movement of the at least one roller across the volume.

3 . The method of claim 2 , wherein vibrating the at least one roller includes superimposing rotational vibration of the at least one roller onto the rotation of the at least one roller.

4 . The method of claim 1 , wherein vibrating the at least one roller includes vibrating the at least one roller in a direction substantially perpendicular to a direction of movement of the at least one roller across the volume.

5 . The method of claim 1 , wherein the at least one roller is coupled to springs, and vibrating the at least one roller includes delivering spring force to the at least one roller.

6 . The method of claim 1 , wherein the at least one roller is coupled to an eccentric motor, and vibrating the at least one roller includes controlling the eccentric motor to a predetermined rotation speed.

7 . The method of claim 1 , wherein the at least one roller is coupled to a voice coil actuator, and vibrating the at least one roller includes actuating the voice coil actuator at a predetermined frequency.

8 . The method of claim 1 , wherein vibrating the at least one roller includes vibrating the at least one roller at a frequency of greater than about 1 kHz or less than about 1 MHz.

9 . The method of claim 1 , wherein the at least one roller includes a wall defining a roller volume, and vibrating the at least one roller includes pulsing pressurized fluid in the roller volume to expand the wall as the at least one roller moves across the powder box.

10 . The method of claim 9 , wherein the pressurized fluid includes air.

11 . The method of claim 9 , wherein the pressurized fluid includes water.

12 . The method of claim 1 , wherein the at least one roller includes a piezoelectric coating on an outer surface of the at least one roller, and vibrating the at least one roller includes sending a pulsed electric signal to the piezoelectric coating as the at least one roller moves across the volume.

13 . The method of claim 1 , further comprising, for each respective layer of a plurality of layers, repeating the steps of moving the at least one roller across the volume, vibrating the at least one roller, and delivering the binder from the print carriage to the respective layer in a predetermined two-dimensional pattern associated with the respective layer to form a three-dimensional object.

14 . The method of claim 13 , wherein one or more of the steps of moving the at least one roller across the volume, vibrating the at least one roller, and delivering the binder from the print carriage to the respective layer is carried out in a first direction across the volume and in a second direction across the volume, and the first direction is different from the second direction.

15 . An additive manufacturing method, the method comprising:
moving at least one roller at a predetermined velocity across a volume defined by a powder box, movement of the at least one roller across the volume spreading a layer of a powder across the volume; vibrating the at least one roller at a predetermined frequency, the predetermined frequency corresponding to a wavelength substantially equal to an average size of particles of the powder as the at least one roller moves across the powder box at the predetermined velocity; and delivering a binder to the layer in a predetermined two-dimensional pattern corresponding to the layer.

16 . The method of claim 15 , wherein vibrating the at least one roller includes vibrating the at least one roller at a frequency of about 1 kHz to about 1 MHz.

17 . The method of claim 15 , wherein moving the at least one roller across the volume includes rotating the at least one roller in a direction counter to a direction of movement of the at least one roller across the volume.

18 . The method of claim 17 , wherein vibrating the at least one roller includes superimposing rotational vibration of the at least one roller onto the rotation of the at least one roller.

19 . The method of claim 15 , wherein vibrating the at least one roller includes vibrating the at least one roller in a direction substantially perpendicular to a direction of movement of the at least one roller across the volume.

20 . The method of claim 15 , further comprising, for each respective layer of a plurality of layers, repeating the steps of moving the at least one roller, vibrating the at least one roller, and delivering the binder to the layer of the powder to form a three-dimensional object.

21 . An additive manufacturing system comprising:
a powder box defining a volume; a print carriage defining at least one ejection orifice, the print carriage movable over the volume, and the print carriage actuatable to eject a binder from the at least one ejection orifice in a direction toward a layer of a powder along the volume as the print carriage moves over the volume; and at least one roller movable over the volume in advance of the print carriage to spread the layer of the powder across the volume, the at least one roller actuatable to vibrate at a predetermined frequency as the at least one roller moves over the volume to transmit vibration from the at least one roller to the powder as the layer is spread across the volume.

22 . The system of claim 21 , wherein the at least one roller is rotatable in a direction counter to a direction of movement of the at least one roller across the volume as the at least one roller moves across the volume.

23 . The system of claim 22 , wherein the at least one roller is actuatable to vibrate as the at least one roller is rotated in the direction counter to the direction of movement of the at least one roller such that vibration of the at least one roller is superimposed on counter rotation of the at least one roller.

Assignees

• Desktop Metal Inc

Inventors

• Myerberg Jonah Samuel
• Fulop Ricardo
• Hoisington Paul A
• Sachs Emanuel Michael
• Gibson Michael Andrew
• Hart Anastasios John
• Vaillancourt Keith
• Garrant Steven
• SCHUSTER Brett

Classifications

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B22F2998/00

  Supplementary information concerning processes or compositions relating to powder metallurgy · CPC title

• B33Y30/00

  Apparatus for additive manufacturing; Details thereof or accessories therefor · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title

• B22F2202/01

  Use of vibrations · CPC title