Hierarchical porous metals with deterministic 3d morphology and shape via de-alloying of 3d printed alloys

Patent metadata

Field	Value
Publication number	US-2022032369-A1
Application number	US-202117502538-A
Country	US
Kind code	A1
Filing date	Oct 15, 2021
Priority date	Oct 23, 2017
Publication date	Feb 3, 2022
Grant date	—

Abstract

The present disclosure relates to a system for using a feedstock to form a three dimensional, hierarchical, porous metal structure with deterministically controlled 3D multiscale porous architectures. The system may have a reservoir for holding the feedstock, the feedstock including a rheologically tuned alloy ink. A printing stage may be used for receiving the feedstock. A processor may be incorporated which has a memory, and which is configured to help carry out an additive manufacturing printing process to produce a three dimensional (3D) structure using the feedstock in a layer-by-layer fashion, on the printing stage. A nozzle may be included for applying the feedstock therethrough onto the printing stage. A de-alloying subsystem may be used for further processing the 3D structure through a de-alloying operation to form a de-alloyed 3D structure having several distinct, differing pore length scales ranging from a digitally controlled macroporous architecture to a nanoporosity introduced by the de-alloying operation.

First claim

1 . A system for using a feedstock to form a three dimensional, hierarchical, porous metal structure with deterministically controlled 3D multiscale porous architectures, the system comprising:
an reservoir for holding the feedstock, the feedstock being formed as a rheologically tuned alloy ink; a printing stage for receiving the feedstock; a processor including a memory and configured to help carry out an additive manufacturing printing process to produce a three dimensional (3D) structure using the feedstock in a layer-by-layer fashion, on the printing stage; a nozzle for applying the feedstock therethrough onto the printing stage; a de-alloying subsystem for further processing the 3D structure through a de-alloying operation to form a de-alloyed 3D structure having several distinct, differing pore length scales ranging from a digitally controlled macroporous architecture to a nanoporosity introduced by the dealloying operation.

2 . The system of claim 1 , wherein the feedstock comprises an alloy powder.

3 . The system of claim 1 , wherein the rheologically tuned alloy ink comprises an ink formed from a plurality of different metal powders and a binder.

4 . The system of claim 1 , wherein the additive manufacturing printing process comprises a direct ink writing (DIW) process.

5 . The system of claim 1 , wherein the additive manufacturing printing process comprises at least one of:
a direct ink writing (DIW) process; a selective laser sintering process; a selective laser melting process; a binder powder bed printing process; a fused deposition modeling process; a projection microstereolithography process; an electrophoretic deposition process; a screen printing process; and an inkjet printing process.

6 . The system of claim 3 , wherein the rheologically tuned alloy ink comprises an ink formed from silver powder and gold powder.

7 . The system of claim 6 , wherein the rheologically tuned alloy ink comprises also comprises an organic binder.

8 . The system of claim 1 , further comprising an annealing subsystem for performing an annealing operation on the 3D structure prior to performing the de-alloying operation.

9 . The system of claim 8 , wherein the annealing subsystem is configured to heat the 3D structure to 0.99%-0.7% of a melting temperature of an alloy being used to form the 3D structure.

10 . The system of claim 9 , wherein the annealing subsystem is configured to maintain the 3D structure heated for between 1 hour to 24 hours.

11 . The system of claim 1 , wherein the de-alloying subsystem enables submerging the 3D structure in an aqueous solution for a predetermined time.

12 . A system for forming a three dimensional, hierarchical, porous metal structure with deterministically controlled 3D multiscale hierarchical pore architectures, the system comprising:
a printing stage; an additive manufacturing system including a processor having a nozzle, and configured to print a three dimensional (3D) structure in a layer-by-layer process by flowing a rheologically tuned ink through the nozzle onto the printing stage and to build up the 3D structure in a layer-by-layer; an annealing subsystem configured to anneal the 3D structure to remove the binder, and to form an alloyed 3D structure; and a de-alloying subsystem configured to de-alloy the alloyed 3D structure to form a hierarchical, nanoporous 3D structure having an engineered, digitally controlled macropore morphology with integrated nanoporosity.

13 . The system of claim 12 , wherein the rheologically tuned ink comprises an ink from a plurality of metal powders and a binder.

14 . The system of claim 12 , wherein the annealing subsystem is configured to heat the 3D structure to 99%-0.7% of the melting temperature of an alloy to be formed as the alloyed 3D structure.

15 . The system of claim 14 , wherein the annealing subsystem is further configured to heat the 3D structure for a predetermined time period from between 1 hour to 24 hours.

16 . The system of 12 , wherein the de-alloying subsystem is configured to enabling submerging the alloyed 3D structure in a solution.

17 . A system for forming a three dimensional, hierarchical, porous metal structure with deterministically controlled 3D multiscale hierarchical pore architectures, the system comprising:
a printing stage; a rheologically tuned, flowable ink including a metal powder and a binder; an additive manufacturing system including a processor for controlling a printing process, and also having a nozzle, and configured to print a three dimensional (3D) structure in a layer-by-layer process by flowing the rheologically tuned ink through the nozzle onto the printing stage, to build up the 3D structure in a layer-by-layer printing operation; an annealing subsystem configured to anneal the 3D structure by heating the 3D structure for a predetermined time period to remove the binder, to form an alloyed 3D structure; and a de-alloying subsystem configured to de-alloy the alloyed 3D structure to form a hierarchical, nanoporous 3D structure having an engineered, digitally controlled macropore morphology with integrated nanoporosity.

18 . The system of claim 17 , wherein the metal powder of the rheologically tuned ink comprises a mixture of a plurality of different metal powders and the binder.

19 . The system of claim 17 , wherein the annealing subsystem is configured to heat the 3D structure to 99%-0.7% of the melting temperature of an alloy to be formed as the alloyed 3D structure, for a predetermined period of time.

20 . The system of claim 19 , wherein the de-alloying subsystem is configured to enabling submerging the alloyed 3D structure in an aqueous solution for a predetermined period of time.

Assignees

• L Livermore Nat Security Llc

Inventors

• Qi Zhen
• Biener Juergen
• Chen Wen
• Duoss Eric
• Spadaccini Christopher
• Worsley Marcus A
• Ye Jianchao
• Zhu Cheng

Classifications

• B22F3/1146 Primary

  After-treatment maintaining the porosity (B22F3/114 takes precedence) · CPC title

• B22F3/1115 Primary

  comprising complex forms, e.g. honeycombs · CPC title

• B22F10/64

  by thermal means (control of energy beam parameters for post heating B22F10/364) · CPC title

• B22F10/18

  by mixing binder with metal in filament form, e.g. fused filament fabrication [FFF] · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title