Material systems for additive manufacturing

Patent metadata

Field	Value
Publication number	US-2021283688-A1
Application number	US-201716328632-A
Country	US
Kind code	A1
Filing date	Dec 14, 2017
Priority date	Dec 14, 2016
Publication date	Sep 16, 2021
Grant date	—

Abstract

Techniques and compositions are disclosed for three-dimensional printing with powder/binder systems including, but not limited to, metal injection molding powder materials, highly-filled polymer composites, and any other materials suitable for handling with various additive manufacturing techniques, and further suitable for subsequent debinding and thermal processing into a final object.

First claim

1 .- 110 . (canceled)

111 . A method of additive manufacturing, the method comprising:
moving one or more nozzles along an extrusion path relative to a build plate; extruding a two component extrudable filament-based feedstock through one more nozzles, the extrusion forming a three-dimensional object along an extrusion path, the feedstock including:
a core having a first toughness and selected to include a binder system and a sinterable powdered metal suspended within the binder system, the binder system comprising a first binder and a second binder, the first binder and second binder including a first polymer;
a jacket formed around the core, the jacket including a second polymer, the jacket having a second toughness greater than the first toughness,
wherein the second toughness is sufficient to be gripped by a feed mechanism without breaking, and sufficiently viscous to be extruded;
exposing the three-dimensional object to a chemical solution, the chemical solution chemically removing a first polymer, wherein the chemically removing of the first polymer occurs during a chemical dissolution of at least a portion of the first binder from the three-dimensional object as the second binder supports a shape of the three-dimensional object; debinding the second binder from the three-dimensional object; and densifying the powder material in the three-dimensional object to form a final part.

112 . The method of claim 111 , wherein the second polymer has a molecular weight greater than a molecular weight of the first polymer.

113 . The method of claim 111 , wherein the first binder and second binder are formed of the same binder.

114 . The method of claim 113 , wherein a concentration of the first binder is lower than a concentration of the second binder.

115 . The method of claim 111 , wherein the filament is on a spool.

116 . The method of claim 111 , wherein the first polymer and the second polymer are identical.

117 . The method of claim 111 , wherein the first polymer and the second polymer are different polymers.

118 . The method of claim 111 , wherein the method further comprises:
lowering, via the jacket, an effective volume fraction; and increasing shrinkage of the three-dimensional object.

119 . The method of claim 111 , wherein the second toughness of the jacket being greater than the first toughness of the core protects the core from unintended deformation or damage.

120 . The method of claim 111 , wherein the primary binder has a molecular weight of greater than about 100,000 g/mol.

121 . The method of claim 111 , wherein the powder material includes one or more of a metal, a metal alloy, or a ceramic.

122 . The method of claim 111 , wherein densifying the powder includes one or more of sintering the three-dimensional object or infiltrating the three-dimensional object with a liquid metal.

123 . The feedstock of claim 111 , wherein the first polymer includes at least one of a thermoplastic polysaccharide, polylactic acid, polyglycolic acid, poly(lactide)-co-(caprolactone), copolymers containing styrene blocks, polyethylene glycol, PEG-PMMA, a urethane ester, and a polyanhydride.

124 . The method of claim 111 , wherein powdered metal in the core corresponds to a first amount, the jacket further comprising a second amount of powdered metal, the second amount of powdered metal in the jacket corresponding to a lower volumetric percentage than the volumetric percentage of the first amount in the core.

125 . The method of claim 111 , wherein the jacket does not include any powdered metal.

126 . A method of additive manufacturing, the method comprising:
moving one or more nozzles along an extrusion path relative to a build plate; extruding a two component extrudable filament-based feedstock through one more nozzles, the extrusion forming a three-dimensional object along an extrusion path, the feedstock including:
a core having a first brittleness and selected to include a binder system and a sinterable powdered metal suspended within the binder system, the binder system comprising a first binder and a second binder, the first binder and second binder including a first polymer;
a jacket formed around the core, the jacket including a second polymer, the jacket having a second brittleness greater than the first brittleness,
wherein the second brittleness is sufficient to be gripped by a feed mechanism without breaking, and sufficiently viscous to be extruded;
exposing the three-dimensional object to a chemical solution, the chemical solution chemically decomposing a first polymer, wherein the chemical decomposition of the first polymer occurs during a chemical dissolution of at least a portion of the first binder from the three-dimensional object as the second binder supports a shape of the three-dimensional object; debinding the second binder from the three-dimensional object; and densifying the powder material in the three-dimensional object to form a final part.

127 . The method of claim 126 , wherein the second polymer has a molecular weight greater than a molecular weight of the first polymer.

128 . The method of claim 126 , wherein the first binder and second binder are formed of the same binder.

129 . The method of claim 126 , wherein a concentration of the first binder is lower than a concentration of the second binder.

130 . The method of claim 126 , wherein the method further comprises:
lowering, via the jacket, an effective volume fraction; and increasing shrinkage of the three-dimensional object.

131 . The method of claim 126 , wherein the second brittleness of the jacket being greater than the first brittleness of the core protects the core from unintended deformation or damage.

132 . The method of claim 126 , wherein the primary binder has a molecular weight of greater than about 100,000 g/mol.

133 . The method of claim 126 , wherein the first polymer and the second polymer are identical.

134 . The method of claim 126 , wherein the first polymer and the second polymer are different polymers.

Assignees

• Desktop Metal Inc

Inventors

• Fulop Ricardo
• Bose Animesh
• Gibson Michael Andrew
• Fontana Richard Remo
• Myerberg Jonah Samuel

Classifications

• B22F10/12

  by photopolymerisation, e.g. stereolithography [SLA] or digital light processing [DLP] · CPC title

• B22F12/90

  Means for process control, e.g. cameras or sensors · CPC title

• B22F12/86

  Serial processing with multiple devices grouped · CPC title

• B22F12/55

  Two or more means for feeding material · CPC title

• B22F12/10

  Auxiliary heating means · CPC title