Infiltratable structures

Patent metadata

Field	Value
Publication number	US-2021291274-A1
Application number	US-201917264253-A
Country	US
Kind code	A1
Filing date	Jul 15, 2019
Priority date	Jul 13, 2018
Publication date	Sep 23, 2021
Grant date	—

Abstract

A method for fabricating an infiltrated object of a desired shape having a high volume fraction of infiltrant using an additively manufactured preform. Using an additive manufacturing technique, the preform is formed with graded macro-porosity. When infiltrated, the void volume of the macro-porosity is filled with infiltrant Optionally, the void volume may be varied across the profile of the object to create a gradient of mechanical properties in the infiltrated object.

First claim

What is claimed:

1 . A method of fabricating a metallic three-dimensional object of a desired shape, comprising the steps of:
forming a build material into a skeleton of the desired shape of the three-dimensional object, the build material including a metal powder and a binder system; wherein the skeleton includes graded macro-porosity having a void volume; debinding at least a portion of the binder system; and infiltrating the skeleton with an infiltrant wherein the void volume of the macro-porosity is filled with the infiltrant.

2 . The method of claim 1 wherein the void volume of the graded macro-porosity in a first section of the skeleton is a first volume fraction of the skeleton that is higher than a second volume fraction of the skeleton in a second section.

3 . The method of claim 1 wherein the void volume of the graded macro-porosity varies as a volume fraction of the skeleton in at least one axis.

4 . The method of claim 1 wherein the void volume of the graded macro-porosity varies as a volume fraction of the skeleton in at least two axes.

5 . The method of claim 1 wherein the void volume of the graded macro-porosity varies as a volume fraction of the skeleton in at least three axes.

6 . The method of claim 1 wherein the step of forming the build material into a skeleton includes bound metal deposition additive manufacturing.

7 . The method of claim 6 wherein the macro-porosity in the skeleton is introduced by controlling at least one parameter in the bound metal deposition additive manufacturing.

8 . The method of claim 7 wherein the macro-porosity in the skeleton is introduced by manipulating a tool pathing of a nozzle.

9 . The method of claim 1 wherein the step of forming the build material into a skeleton includes powder bed binder jetting additive manufacturing.

10 . The method of claim 9 wherein the macro-porosity in the skeleton is introduced by controlling at least one of a droplet size and a binder saturation.

11 . The method of claim 1 , wherein the metal powder is an aluminum alloy, the infiltrant is aluminum, and further comprising the step of nitriding the aluminum alloy prior to infiltration.

12 . The method of claim 1 wherein the void volume of the graded macro-porosity is defined by a gyroid infill pattern.

13 . A method of fabricating a metallic three-dimensional object of a desired shape, comprising the steps of:
depositing a plurality of successive layers of build material to form a skeleton having graded macro-porosity, wherein the build material includes a binder system and a metal powder; removing at least a portion of the binder system; infiltrating the skeleton with an infiltrant to fill at least a portion of a void volume of the graded macro-porosity; and wherein the metal powder is a first metal alloy and the infiltrant is a second metal alloy.

14 . The method of claim 13 wherein the void volume of the graded macro-porosity varies as a volume fraction of the skeleton in at least one axis.

15 . The method of claim 13 wherein the macro-porosity in the skeleton is introduced by controlling at least one parameter in a bound metal deposition additive manufacturing process.

15 . The method of claim 13 wherein the macro-porosity in the skeleton is introduced by controlling at least one parameter in a powder bed binder jetting additive manufacturing process.

17 . A method of fabricating a metallic three-dimensional object of a desired shape, comprising the steps of:
additively manufacturing a skeleton of an aluminum alloy and binder system having a graded macro-porosity; removing at least a portion of the binder system; nitriding the aluminum alloy to form an aluminum nitride skeleton; infiltrating the aluminum nitride skeleton with aluminum wherein a void space of the macro-porosity is occupied by aluminum.

18 . The method of claim 1 wherein the void volume of the graded macro-porosity varies as a volume fraction of the skeleton in at least one axis.

19 . The aluminum nitride skeleton is dimensionally stable in the presence of the infiltrant during an infiltration process effective to infiltrate the void space of the macro-porosity.

20 . The method of claim 17 wherein the void volume of the graded macro-porosity is defined by a gyroid infill pattern.

Assignees

• Desktop Metal Inc

Inventors

• Sercombe Timothy
• Gibson Michael Andrew
• Benn Ellen Elizabeth

Classifications

• B22F10/34 Primary

  of powder characteristics, e.g. density, oxidation or flowability · CPC title

• B22F10/14 Primary

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

• B22F12/22

  Driving means · CPC title

• B22F12/13

  to preheat the material · CPC title

• B22F10/25

  Direct deposition of metal particles, e.g. direct metal deposition [DMD] or laser engineered net shaping [LENS] · CPC title