Method and apparatus for producing three-dimensional objects

Patent metadata

Field	Value
Publication number	US-2016303687-A1
Application number	US-201615190877-A
Country	US
Kind code	A1
Filing date	Jun 23, 2016
Priority date	Jul 15, 2009
Publication date	Oct 20, 2016
Grant date	—

Abstract

The invention concerns a method for producing three-dimensional objects ( 6 ) layer by layer using a powdery material ( 7 ) which can be solidified by irradiating it with a high-energy beam ( 4 ), said method comprising the steps of: applying a first layer of powdery material onto a working area ( 5 ); solidifying a part of said first layer by irradiating it with a high-energy beam; and applying a second layer ( 8 ) of powdery material onto the first, partly solidified layer. The invention is characterized in that the method comprises the step of: determining a rate at which the temperature of the second layer ( 8 ) increases after application onto the first layer. The invention also concerns an apparatus configured to operate according to the above method.

First claim

1 . Apparatus ( 1 ) for producing three-dimensional objects ( 6 ) layer by layer using a powdery material ( 7 ) which can be solidified by irradiating it with a high-energy beam ( 4 ), said apparatus comprising:
a working table onto which layers of said powdery material ( 7 ) are to be placed; at least one laser source emitting said high-energy beam ( 4 ) for irradiating said powdery material ( 7 ); a temperature sensing device; and at least one control unit, wherein said apparatus is configured, via said at least one control unit for:
applying a first layer of said powdery material onto said working area ( 5 );
solidifying a part of said first layer by irradiating it with said high-energy beam;
applying a second layer ( 8 ) of said powdery material onto the first, partly solidified layer;
determining a rate at which the temperature of the second layer ( 8 ) increases after application onto the first layer; and
determining a layer thickness of the second layer based upon the determined rate at which the temperature of the second layer ( 8 ) increases after application onto the first layer, wherein the determining of the layer thickness of the second layer involves performing a plurality of sequential temperature measurements before the second layer ( 8 ) reaches a maximum temperature (T 1 ), and the maximum temperature (T 1 ) represents a point in time at which a rate that heat is conducted from the first layer equals a rate that heat is radiated away from an upper surface of the second layer ( 8 ), such that upon reaching the maximum temperature (T 1 ), the temperature of the second layer ( 8 ) is no longer increasing.

2 . Apparatus according to claim 1 , wherein the control unit of the apparatus is further configured for performing the plurality of sequential temperature measurements in the same at least one position of said second layer ( 8 ).

3 . Apparatus according to claim 1 , wherein the control unit of the apparatus is further configured for fitting a mathematical function to data obtained from said plurality of sequential temperature measurements.

4 . Apparatus according to claim 1 , wherein the control unit of the apparatus is further configured for measuring said temperature in said at least one position of said second layer by measuring the temperature in a plurality of positions of said second layer ( 8 ), wherein said plurality of positions are distributed over the second layer ( 8 ).

5 . Apparatus according to claim 1 , wherein the temperature sensing device is a thermographic camera ( 14 ).

6 . Apparatus according to claim 5 , wherein the the thermographic camera ( 14 ) is directed towards an upper surface of the second layer ( 8 ).

7 . Apparatus according to claim 1 , wherein the control unit of the apparatus is further configured for comparing the determined temperature increase rate with at least one reference value.

Assignees

• Arcam Ab

Inventors

• Ljungblad Ulric

Classifications

• B23K26/342 Primary

  Build-up welding · CPC title

• B22F10/368

  Temperature or temperature gradient, e.g. temperature of the melt pool · CPC title

• B22F12/50

  Means for feeding of material, e.g. heads · CPC title

• B22F12/41

  characterised by the type, e.g. laser or electron beam · CPC title

• B29C64/153 Primary

  using layers of powder being selectively joined, e.g. by selective laser sintering or melting · CPC title