Techniques for casting from additively fabricated molds and related systems and methods

Patent metadata

Field	Value
Publication number	US-11745392-B2
Application number	US-202016871646-A
Country	US
Kind code	B2
Filing date	May 11, 2020
Priority date	May 17, 2017
Publication date	Sep 5, 2023
Grant date	Sep 5, 2023

Abstract

According to some aspects, a method is provided of casting an object from a mold, the method comprising obtaining a mold comprising a hollow shell of rigid material, the material comprising a thermoset polymer having a plurality of pores formed therein, providing a metal and/or ceramic slurry into an interior of the mold, exposing at least part of the mold to a low pressure environment so that a net flow of gas is produced from the interior of the mold into the low pressure environment. According to some aspects, a method of forming a porous mold is provided. According to some aspects, a photocurable liquid composition is provided, comprising a liquid photopolymer resin, particles of a solid material, in an amount between 30% and 60% by volume of the composition, and a water-soluble liquid.

First claim

What is claimed is:

1. A method of forming a porous object, the method comprising:
forming, via additive fabrication, an object comprising a hollow shell of rigid material, wherein the material comprises a thermoset polymer and a plurality of solid particles embedded within the polymer; and
removing at least some of the solid particles from the object, thereby forming a plurality of pores in the hollow shell.

2. The method of claim 1 , wherein the solid particles include particles of NaHCO 3 , and wherein removing the at least some of the solid particles comprises reacting the solid particles with an acidic liquid.

3. The method of claim 1 , wherein the solid particles include particles of a water-soluble salt, and wherein removing the at least some of the solid particles comprises dissolving the solid particles in water.

4. The method of claim 1 , wherein removing the at least some of the solid particles comprises applying heat to the object.

5. The method of claim 1 , wherein forming the object comprises applying radiation to a mixture comprising a liquid photopolymer, thereby curing the liquid photopolymer into the thermoset polymer.

6. The method of claim 1 , wherein a mean size of the plurality of pores is between 20 μm and 100 μm.

7. The method of claim 6 , wherein the mean size of the plurality of pores is between 40 μm and 60 μm.

Assignees

• Formlabs Inc

Inventors

• Mccarthy Alex
• Lobovsky Maxim
• Galese Martin

Classifications

• B22F3/22

  for producing castings from a slip · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B29C33/3842 Primary

  Manufacturing moulds, e.g. shaping the mould surface by machining · CPC title

• B22D29/00

  Removing castings from moulds, not restricted to casting processes covered by a single main group; Removing cores; Handling ingots {(B22D13/10, B22D11/124, B22D17/00 take precedence)} · CPC title

• B28B7/346

  Manufacture of moulds · CPC title