Process for melting/sintering powder particles for layer-by-layer production of three-dimensional objects

Patent metadata

Field	Value
Publication number	US-2017274591-A1
Application number	US-201715468465-A
Country	US
Kind code	A1
Filing date	Mar 24, 2017
Priority date	Mar 24, 2016
Publication date	Sep 28, 2017
Grant date	—

Abstract

A process for melting/sintering powder particles for layer-by-layer production of three-dimensional objects is performed by a)applying a layer of a powder material solidifiable under the action of electromagnetic radiation, b) heating the powder material to not more than 10 K below the melting point according to DIN 53765 by a radiation from a heat-radiating element whose maximum radiation intensity is at a wavelength of 5000 nm or at longer wavelengths, c) selective melting/sintering of at least a region of the powder material which corresponds to the cross section of the three-dimensional object, d)repeating steps a) to c) until the three-dimensional object is obtained.

First claim

1 . A process for layer-by-layer production of three-dimensional objects, said process comprising:
a) applying a layer of a powder material solidifiable under the action of electromagnetic radiation, b) heating the powder material to not more than 10 K below the melting point according to DIN 53765 by a radiation from a heat-radiating element whose maximum radiation intensity is at a wavelength of 5000 nm or at longer wavelengths, c) selective melting/sintering of at least a region of the powder material which corresponds to the cross section of the three-dimensional object, d) repeating steps a) to c) until the three-dimensional object is obtained.

2 . The process according to claim 1 , wherein the irradiation power of the heat-radiating element is at least 2000 W/m 2 based on the vertically projected area of the powder bed that is to be heated.

3 . The process according to claim 1 , wherein the area of the heat-radiating element is at least 100% of the vertically projected area of the powder bed that is to be heated.

4 . An apparatus for layer-by-layer production of three-dimensional objects, comprising:
heat-radiating elements, whose area, which give off the electromagnetic rays to the surface of the powder bed, is at least 100% of the vertically projected area of the powder bed which is bounded by the build frame.

5 . The apparatus according to claim 4 , wherein the heat-radiating elements are configured such that the intensity maximum of the radiation from the heat-radiating elements is at a wavelength of at least 5000 nm.

6 . The apparatus according to claim 4 , wherein the heat-radiating elements are configured such that the total emissivity in the direction of the face normal of the heat-radiating elements is at least 0.2.

7 . A three-dimensional object, produced by a process according to claim 1 .

8 . The process according to claim 1 , wherein the powder material has an absorptivity at wavelengths above 5000 nm of at least 0.8.

Assignees

• Evonik Degussa Gmbh

Inventors

• Grebe Maik
• Diekmann Wolfgang
• Hessel-Geldmann Sigrid
• Kreutz Juergen

Classifications

• B33Y80/00

  Products made by additive manufacturing · CPC title

• B33Y30/00

  Apparatus for additive manufacturing; Details thereof or accessories therefor · CPC title

• B29C64/295

  Heating elements · CPC title

• B29K2077/00

  Use of {PA, i.e.} polyamides, e.g. polyesteramides {or derivatives thereof}, as moulding material · CPC title

• B29K2995/0012

  having particular thermal properties · CPC title