Layer Spreading and Compaction in Binder Jet 3D Printing

Patent metadata

Field	Value
Publication number	US-2022355381-A1
Application number	US-202117525718-A
Country	US
Kind code	A1
Filing date	Nov 12, 2021
Priority date	May 4, 2021
Publication date	Nov 10, 2022
Grant date	—

Abstract

A method of conditioning layers of build material powder for metal additive manufacturing including depositing an amount of build material powder on a work surface, the amount of build material powder having a lower surface separated from an upper surface by a height. A roller is traversed across the work surface in a first direction while rotating the roller in a direction opposed to the first direction. During the step of traversing the roller, a lower surface of the roller extends below the upper surface of the amount of build material powder by a distance. The roller has a surface conditioning configured to, in conjunction with a controlled speed of the rotation of the roller, provide a powder density in a compacted layer within a predetermined powder density range.

First claim

What is claimed:

1 . A method of conditioning layers of build material powder for metal additive manufacturing, comprising the steps of:
depositing an amount of build material powder on a work surface, the amount of build material powder having a lower surface separated from an upper surface by a height; traversing a roller across the work surface in a first direction while rotating the roller in a direction opposed to the first direction; wherein during the step of traversing the roller, a lower surface of the roller extends below the upper surface of the amount of build material powder by a distance; and wherein the roller has a surface conditioning configured to, in conjunction with a controlled speed of the rotation of the roller, provide a powder density in a compacted layer within a predetermined powder density range.

2 . The method of claim 1 wherein the controlled speed of the rotation of the roller and a size of the surface conditioning are selected according to characteristics of the build material powder.

3 . The method of claim 1 wherein the controlled speed of the rotation of the roller is varied during the step of traversing the roller.

4 . The method of claim 1 wherein step of traversing the roller compacts the new layer of build material powder.

5 . The method of claim 1 wherein the surface conditioning is a roughness.

6 . The method of claim 1 wherein during the step of traversing the roller, a wiper is disposed against a forward surface of the roller and configured to reduce adherence of the build material powder to the roller.

7 . The method of claim 1 wherein during the step of traversing the roller, varying the speed in which the roller is traversed in the first direction.

8 . The method of claim 5 wherein the speed in which the roller is traversed is increased.

9 . The method of claim 1 wherein the surface conditioning is an arithmetic mean roughness between and inclusive of 0.1 and 0.5 μm.

10 . The method of claim 1 wherein the work surface is a build plate.

11 . The method of claim 1 wherein the work surface is a previously deposited layer of the build material powder.

12 . The method of claim 1 wherein, during the step of traversing, depositing an amount of powder in advance of the roller.

13 . The method of claim 1 wherein the steps of depositing an amount of build material and traversing the roller are done simultaneously.

14 . The method of claim 1 wherein the predetermined powder density range is selected from the group of 55%-64%, 58-62% and 60-61%.

15 . A system for conditioning layers of build material powder in metal additive manufacturing, comprising:
a powder dispensing system configured to deposit an amount of build material powder on a work surface, the amount of build material powder having a lower surface separated from an upper surface by a height; a roller configured to traverse the work surface in a first direction while rotating the roller in a direction opposed to the first direction; wherein the roller is configured to, while traversing, have a lower surface of the roller that extends below the upper surface of the amount of build material powder by a distance; and wherein the roller has a surface conditioning configured to, in conjunction with a controlled speed of the rotation of the roller, provide a powder density in a compacted layer within a predetermined powder density range.

16 . The system of claim 15 wherein the controlled speed of the rotation of the roller is configured to be increased as the roller traverses the work surface.

17 . The system of claim 15 wherein the surface conditioning is a circumferential texturing.

18 . The system of claim 15 further comprising a wiper disposed against a forward surface of the roller and configured to reduce adherence of the build material powder to the roller during traversal of the roller.

19 . The system of claim 15 wherein the surface conditioning is an arithmetic mean roughness between and inclusive of 0.1 and 0.5 μm.

20 . A method of conditioning layers of build material powder for metal additive manufacturing, comprising the steps of:
depositing a new layer of build material powder on a work surface, the layer of build material powder having a lower surface separated from an upper surface by a height; traversing a roller over a work surface in a first direction while rotating the roller in a direction opposed to the first direction; wherein during the step of traversing the roller, a lower surface of the roller extends below the upper surface of the new layer of build material powder by a distance; wherein the roller has a surface conditioning configured to recirculate the build material powder in the new layer of build material powder.

Assignees

• Desktop Metal Inc

Inventors

• Hudelson George
• Barbati Alexander C

Classifications

• B22F12/63

  Rollers · CPC title

• B22F10/14

  by jetting of binder onto a bed of metal powder · CPC title

• B22F10/37 Primary

  of powder bed aspects, e.g. density · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B33Y30/00 Primary

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