Controlling light penetration for stereolithographic manufacturing of dense objects

Patent metadata

Field	Value
Publication number	US-2018133955-A1
Application number	US-201715812845-A
Country	US
Kind code	A1
Filing date	Nov 14, 2017
Priority date	Nov 14, 2016
Publication date	May 17, 2018
Grant date	—

Abstract

Systems, methods, components, and materials are disclosed for stereolithographic fabrication of three-dimensional objects. A resin including particles dispersed in a binder system can be substantially transparent to light of a wavelength sufficient to cure at least one component of the binder system. A green object can be formed by activation light penetrating into each layer of a plurality of layers of the resin in a layer-by-layer process to crosslink, polymerize, or both, at least one component of the binder system in successive layers of the resin to one another. Through subsequent processing, the green object can be densified to form a metal object, a ceramic object, or a combination thereof.

First claim

What is claimed is:

1 . A resin comprising:
particles of a first material; particles of a second material, the second material different from the first material; and a binder system in which the particles of the first material and the particles of the second material are suspended, the particles of the first material substantially transparent to light of a wavelength sufficient to crosslink, polymerize, or both, at least one component of the binder system.

2 . The resin of claim 1 , wherein the particles of the first material and the particles of the second material are substantially homogeneously suspended in the binder system.

3 . The resin of claim 1 , wherein the particles of the second material are substantially opaque to light of the wavelength sufficient to crosslink, polymerize, or both, the at least one component of the binder system.

4 . The resin of claim 1 , wherein the particles of the second material have an average size less than the wavelength of the light sufficient to crosslink, polymerize, or both, the at least one component of the binder system.

5 . The resin of claim 1 , wherein the particles of the first material include a ceramic.

6 . The resin of claim 1 , wherein the particles of the second material include a metal.

7 . The resin of claim 1 , wherein the first material is chemically convertible to the second material.

8 . The resin of claim 7 , wherein the first material is chemically convertible to the second material via thermally-activated decomposition or reduction.

9 . The resin of claim 1 , wherein the first material is a metal oxide reduceable to form a metal.

10 . The resin of claim 1 , wherein the first material includes a ceramic, an intermetallic, or both, and the particles of the first material are chemically convertible to a first metal, and the particles of a second material include a second metal alloyable with the first metal.

11 . The resin of claim 10 , wherein the particles of the first material are in a relative concentration to the particles of the second material such that an alloy of the first metal and the second metal meets a predetermined material standard.

12 . The resin of claim 10 , wherein an oxide of the first metal is less chemically stable than an oxide of the second metal.

13 . The resin of claim 1 , wherein the binder system includes a first binder and a second binder, the first binder different from the second binder and in a mixture with the first binder, and the first binder substantially non-reactive under exposure to the wavelength of light sufficient to crosslink or polymerize the second binder.

14 . The resin of claim 13 , wherein the first binder is extractable from the second binder following exposure of the second binder to the wavelength of light sufficient to crosslink or polymerize the second binder.

15 . A method of additive manufacturing of a three-dimensional object, the method comprising:
providing a layer of a resin on a media source, the resin including particles of a first material, particles of a second material, the second material different from the first material, and a binder system in which the particles of the first material and the particles of the second material are suspended; directing light energy in a predetermined pattern onto the layer to cure the resin on a substrate carried by a build plate, the particles of the first material substantially transparent to the light energy, and the light energy crosslinking, polymerizing, or both, at least one component of the binder system; and for each layer of a plurality of layers, repeating the steps of providing each respective layer of the resin, and directing light energy in a predetermined pattern onto each respective layer of the resin to form a three-dimensional object.

16 . The method of claim 15 , wherein the light energy directed onto each layer penetrates the respective layer to bond successive layers of the plurality of layers of the three-dimensional obj ect.

17 . The method of claim 15 , further comprising sintering the three-dimensional object, the sintering transforming the particles of the first material to a metal or an additive in a metallic alloy.

18 . The method of claim 15 , further comprising removing the binder system from the three-dimensional object through a plurality of debinding processes.

19 . The method of claim 15 , further comprising infiltrating the three-dimensional object with a liquid metal.

20 . The method of claim 19 , wherein infiltrating the three-dimensional object with the liquid metal includes replacing the binder system with the liquid metal.

Assignees

• Desktop Metal Inc

Inventors

• Gibson Michael Andrew

Classifications

• B29C64/129

  characterised by the energy source therefor, e.g. by global irradiation combined with a mask · CPC title

• B29C64/165

  using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber · CPC title

• B29C64/124 Primary

  using layers of liquid which are selectively solidified · CPC title

• A61K6/833

  Glass-ceramic composites · CPC title

• A61K6/822

  comprising rare earth metal oxides · CPC title