US 9,114,571 B2Granted

Method for reducing stress in three dimensional model

AssigneeSolidscape, Inc.

InventorsXiaorong You, Jennifer Elizabeth Gingras, Calvin McCoy Winey, John T. Wigand

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Abstract

An apparatus and method of fabricating a three-dimensional model which reduces occurrence of one a hairline crack(s), stress fracture(s), break(s), flaw(s) and/or other imperfection(s) in the final three-dimensional model. The method comprising the steps of selecting the model material, selecting the sacrificial material, and adding at least one additive to the sacrificial material for at least one of increasing the thermal conductivity, decreasing a coefficient of thermal expansion or decreasing an ability of the sacrificial material to transmit stress to the model material. The three-dimensional composite model is built by depositing a plurality of layers one on top of another. Following completion of the three-dimensional composite model, using at least one of the increase in the thermal conductivity, the decrease in the coefficient of thermal expansion and the decrease in the ability of the composite sacrificial material to transmit stress to the model material for removing the composite sacrificial material from the model material without creating any hairline crack(s), stress fracture(s), break(s), flaw(s) and/or other imperfection(s) in the final three-dimensional model.

Claims20

Dependent claims

A method of fabricating a three-dimensional model which minimizes occurrence of any stress flaw within the three-dimensional model in which the three-dimensional model is formed from a sacrificial material and a model material, and the method comprising the steps of:

selecting a desired model material;
selecting a desired sacrificial material having a first density;
selecting at least one additive having a second density, the second density of the at least one additive being ±10% of the first density of the sacrificial material;
adding the at least one additive to the sacrificial material for at least one of:
increasing a thermal conductivity of the sacrificial material, decreasing a coefficient of thermal expansion of the sacrificial material and decreasing an ability of the sacrificial material to transmit stress to the model material;
forming a uniform composite sacrificial material by dispersing the at least one additive within the sacrificial material uniformly, and suspending the at least one additive within the sacrificial material and minimizing a likelihood that the at least one additive will separate and settle from the sacrificial material;
building a three-dimensional composite model by depositing a plurality of layers, one on top of another, with each layer comprising selective deposition of at least one of the composite sacrificial material and the model material;
and
following completion of the three-dimensional composite model, separating the composite sacrificial material from the model material by a dewaxing process, and during the dewaxing process, using at least one of the increase in the thermal conductivity of the sacrificial material, the decrease in the coefficient of thermal expansion of the sacrificial material and the decrease the ability of the sacrificial material to transmit stress to the model material to remove the composite sacrificial material from the model material without creating any stress flaws in the three-dimensional model.

6 more elements

A method of fabricating a three-dimensional model comprising the steps of:

selecting a desired model material;
selecting a desired sacrificial material with a first density;
selecting an at least one additive having:
(a) a second density which is ±5% of the first density of the sacrificial material, (b) a particle size of about 500 nm or less, and (c) a coefficient of thermal expansion that is at least 10% less than a coefficient of thermal expansion of the sacrificial material so that a decrease in the coefficient of thermal expansion of the at least one additive thus decreases a rate at which the composite sacrificial material expands when heated;
forming a uniform composite sacrificial material and minimizing a likelihood that the at least one additive will separate and settle from the sacrificial material by dispersing the at least one additive within the sacrificial material uniformly and suspending the at least one additive within the sacrificial material;
building a three-dimensional composite model by depositing a plurality of layers, one on top of another, with each layer comprising selective deposition of at least one of the composite sacrificial material and the model material;
and
following completion of the three-dimensional composite model, separating the composite sacrificial material from the model material to fabricate the three-dimensional model.

5 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/661,287Filed 26 Oct 2012 · us provisional application
Priority: 27 Oct 2011
Published: US 2013/0119577 A116 May 2013
Granted: 25 Aug 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification8 codes

B29C 71/02
After-treatment of articles without altering their shape; Apparatus therefor: thermal after-treatment
B29C 33/448
With means for, or specially constructed to facilitate, the removal of articles, e.g. of undercut articles: destructible
B29C 64/40
Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive…
B33Y 70/00
Materials specially adapted for additive manufacturing