Managing thermal contributions between layers during additive manufacturing

Patent metadata

Field	Value
Publication number	US-11179894-B2
Application number	US-201616094174-A
Country	US
Kind code	B2
Filing date	May 12, 2016
Priority date	May 12, 2016
Publication date	Nov 23, 2021
Grant date	Nov 23, 2021

Abstract

In an example, a method includes forming a first layer of build material to be processed in object generation and selectively applying at least one print agent on to the first layer based on a print instruction for the first layer. Energy may be applied to the first layer to cause fusion in at least a region thereof, and at least one temperature associated with a thermal contribution of the first layer to a subsequent layer of build material to be processed in object generation may be measured. It may be determined if a temperature condition indicative of a departure from an anticipated thermal contribution of the first layer to a region of subsequent layer exists. If such a temperature condition does exist, a print instruction for applying print agent to the region of the subsequent layer based on the temperature condition may be determined.

First claim

The invention claimed is:

1. An additive manufacturing apparatus comprising:
an agent distributor to selectively apply liquid fusing agent to a first layer of build material formed on a print bed according to print instructions for the first layer;
an energy source to apply energy to fuse at least one region of the build material receiving the applied fusing agent;
a temperature sensor to measure a temperature of each of a plurality of locations of the first layer of build material formed on the print bed; and
processing circuitry comprising:
a thermal analysis module programmed to determine, using the measurements of the temperature sensor, if a thermal contribution of the first layer of build material to a region of a subsequent layer of build material to be processed in object generation according to print instructions for the subsequent layer exceeds a threshold temperature; and
a control data module programmed to determine, based on the determination of the thermal analysis module, control data for applying fusing agent to the region of the subsequent layer, and to adjust the print instructions for the subsequent layer by reducing an amount of the fusing agent to be applied to the region of the subsequent layer if the thermal contribution exceeds the threshold temperature.

2. An additive manufacturing apparatus according to claim 1 in which the control data module is programmed to modify the print instructions for the subsequent layer if the thermal analysis module identifies at least one region of the plurality of locations in which the thermal contribution of the first layer of build material to the subsequent layer of build material to be processed in object generation exceeds the threshold temperature.

3. An additive manufacturing apparatus according to claim 1 in which the thermal analysis module is programmed to determine if the thermal contribution of the first layer of build material to the subsequent layer of build material to be processed in object generation exceeds the threshold temperature based on a thermal model.

4. An additive manufacturing apparatus according to claim 1 in which the temperature sensor is configured to measure the temperature of each of a plurality of locations of the subsequent layer of build material to be processed in object generation before fusing agent is applied thereto.

5. An additive manufacturing apparatus according to claim 1 in which the temperature sensor comprises a thermal imaging camera.

6. An additive manufacturing apparatus according to claim 1 , wherein the control data module is programmed to adjust the control data by:
an increase in an amount of fusion-reduction agent to be applied to the region of the subsequent layer.

7. An additive manufacturing apparatus according to claim 1 , wherein the control data module is programmed to adjust the print instructions for the subsequent layer by adjusting a contone level of the fusing agent to be applied to the region of the subsequent layer if the thermal contribution exceeds the threshold temperature.

8. An additive manufacturing apparatus according to claim 1 , wherein the control data module is programmed to reduce the amount of fusing agent to be applied to the region of the subsequent layer where the thermal contribution of the first layer exceeds the threshold temperature, if the thermal contribution exceeds the threshold temperature.

9. An additive manufacturing apparatus according to claim 1 , wherein the control data module is programmed to adjust the print instructions for the subsequent layer by adjusting a concentration of the fusing agent to be applied to the region of the subsequent layer if the thermal contribution exceeds the threshold temperature.

10. An additive manufacturing apparatus according to claim 1 , wherein the control data module is programmed to adjust the amount of the fusing agent to be applied to the region of the subsequent layer with a proportional-integral-derivative (PID) calculation.

11. An additive manufacturing apparatus according to claim 1 , wherein the control data module is programmed to adjust the print instructions for the subsequent layer by applying a mask to the print instructions for applying the fusing agent to the region of the subsequent layer.

12. A method of using the additive manufacturing apparatus according to claim 1 , the method comprising:
forming the first layer of build material;
selectively applying the fusing agent to the first layer based on the print instructions for the first layer;
applying the energy to the first layer to cause fusion in the at least one region thereof;
measuring the temperature of each of the plurality of locations of the first layer;
determining, using the thermal analysis module, if a thermal contribution of the first layer to the region of the subsequent layer of build material to be processed in object generation according to print instructions for the subsequent layer exceeds the threshold temperature; and
determining, using the control data module, the control data for applying fusing agent to the region of the subsequent layer.

13. A method according to claim 12 further comprising forming the subsequent layer of build material and measuring the temperature of at least one location of the subsequent layer before any of the fusing agent is applied thereto.

14. A method according to claim 13 in which determining if the thermal contribution of the first layer of build material to the region of the subsequent layer of build material exceeds the threshold temperature comprises identifying the region of the subsequent layer of build material to be processed in which the threshold temperature would be exceeded.

15. A method according to claim 12 in which determining the control data for applying fusing agent to the region of the subsequent layer comprises modifying the print instructions for the subsequent layer.

16. A method according to claim 12 in which determining if the thermal contribution of the first layer of build material to the region of the subsequent layer of build material exceeds the threshold temperature comprises identifying the region of the subsequent layer of build material in which the threshold temperature would be exceeded.

17. A method according to claim 12 further comprising determining a function based on the at least one of the measured temperatures and in which determining the control data for applying fusing agent to the region of the subsequent layer comprises convolving the function and the print instructions for the subsequent layer.

18. A method according to claim 12 in which determining the control data for applying fusing agent to the region of the subsequent layer comprises modifying the print instructions for the subsequent layer by applying at least one mask to the print instructions for the subsequent layer, wherein the mask is indicative of at least one of:
at least one portion of the print instructions for the subsequent layer to be modified by said modification; and
at least one portion of the print instructions for the subsequent layer to be left unmodified by said modification.

Assignees

• Hewlett Packard Development Co

Inventors

• Fornos Pol
• Puigardeu Aramendia Sergio
• Vilajosana Xavier

Classifications

• B29C70/32

  on a rotating mould, former or core · CPC title

• B29C64/124

  using layers of liquid which are selectively solidified · CPC title

• B33Y50/02

  for controlling or regulating additive manufacturing processes · CPC title

• B33Y30/00

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

• B29C64/165

  using a combination of solid and fluid materials, e.g. a powder selectively bound by a liquid binder, catalyst, inhibitor or energy absorber · CPC title