Nanoparticles in binder jetting fabrication of metal objects

Patent metadata

Field	Value
Publication number	US-2021276083-A1
Application number	US-201816328350-A
Country	US
Kind code	A1
Filing date	Feb 21, 2018
Priority date	Feb 21, 2017
Publication date	Sep 9, 2021
Grant date	—

Abstract

Devices, systems, and methods are directed to the use of nanoparticles for improving strength fabrication of three-dimensional objects formed through layer-by-layer process in which an ink is delivery of a binder delivered onto successive layers of a powder of inorganic particles in a powder bed. More specifically, nanoparticles of inorganic material can may be introduced into one or more layers of the metal powder in the powder bed and thermally processed to facilitate sinter necking, in the powder bed, of the metal particles forming the three-dimensional object. Such sinter necking in the powder bed can may improve strength of the three-dimensional objects being fabricated and, also or instead, can may reduce the likelihood of defects associated with subsequent processing of the three-dimensional objects (e.g., slumping and shrinking in a final sintering stage and/or inadequate densification of the final part).

First claim

1 .- 205 . (canceled)

206 . An additive manufacturing method, the method comprising:
spreading a plurality of layers of a powder across a powder bed; distributing an ink along at least a portion of each layer as the respective layer of the powder is on top of the powder bed, the ink including first nanoparticles and second nanoparticles, the first nanoparticles including a metal oxide, the second nanoparticles including a reducing agent of the metal oxide, the distribution of the ink in the plurality of layers defining at least one three-dimensional object in the powder bed; and in the at least one three-dimensional object, reducing at least a portion of the metal oxide to a metal via a reduction reaction with the reducing agent.

207 . The method of claim 206 , wherein the metal oxide is reduced via the reducing agent with the three-dimensional object in a vacuum environment.

208 . The method of claim 206 , wherein reducing the metal oxide of the first nanoparticles with the reducing agent of the second nanoparticles includes sintering the three-dimensional object.

209 . The method of claim 208 , wherein sintering the three-dimensional object includes heating the three-dimensional object in the powder bed.

210 . The method of claim 206 , wherein the ink further includes a carrier in which the first nanoparticles and the second nanoparticles are dispersed, and the first nanoparticles are substantially inert with respect to the second nanoparticles in the carrier.

211 . The method of claim 219 , wherein the carrier is an aqueous medium.

212 . The method of claim 210 , wherein the carrier includes a polymer.

213 . The method of claim 206 , wherein the metal oxide of the first nanoparticles is one or more of nickel oxide or copper oxide.

214 . The method of claim 206 , wherein the reducing agent includes carbon.

215 . The method of claim 214 , wherein the reducing agent is carbon black.

216 . The method of claim 206 , wherein the powder includes inorganic particles.

217 . The method of claim 216 , wherein the inorganic particles include a first metal.

218 . The method of claim 217 , wherein reducing the metal oxide with the reducing agent forms a second metal.

219 . The method of claim 218 , wherein the first metal and the second metal are alloyable with one another.

220 . The method of claim 219 , wherein the first metal and the second metal are alloyable with one another to form stainless steel.

221 . A three-dimensional object including:
a plurality of layers of a powder, the powder including inorganic particles; first nanoparticles distributed along at least a portion of each layer of the plurality of layers of the powder, the first nanoparticles including a metal oxide; and second nanoparticles distributed along at least a portion of each layer of the plurality of layers of the powder, the second nanoparticles including a reducing agent of the metal oxide, and the distribution of the first nanoparticles and the second nanoparticles in the plurality of layers defining the three-dimensional object.

222 . The three-dimensional object of claim 221 , wherein the inorganic particles include a first metal, and the metal oxide is reducible, via reaction with the reducing agent, to a second metal.

223 . The three-dimensional object of claim 222 , wherein the first metal and the second metal are alloyable with one another.

224 . The three-dimensional object of claim 222 , wherein the inorganic particles have a sinter temperature greater than respective sinter temperatures of the first nanoparticles and the second nanoparticles.

Assignees

• Desktop Metal Inc

Inventors

• Barbati Alexander C
• Fontana Richard Remo
• Gibson Michael Andrew
• Hudelson George

Classifications

• B22F1/0547

  Nanofibres or nanotubes · CPC title

• B22F1/16

  Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) · CPC title

• B22F1/054

  Nanosized particles · CPC title

• B22F1/102

  Metallic powder coated with organic material · CPC title

• B22F1/052

  characterised by a mixture of particles of different sizes or by the particle size distribution · CPC title