Controlling heating in additive manufacturing

Patent metadata

Field	Value
Publication number	US-10960606-B2
Application number	US-201616097266-A
Country	US
Kind code	B2
Filing date	Jul 22, 2016
Priority date	Jul 22, 2016
Publication date	Mar 30, 2021
Grant date	Mar 30, 2021

Abstract

According to some examples, a method comprises measuring, using a detector, a temperature of at least a portion of a layer of build material formed on a print bed associated with an additive manufacturing apparatus. The additive manufacturing apparatus may include a heating module to direct heat towards successive layers of build material during a series of successive passes over the build material. The method may further comprise determining, using a processor, based at least in part on the measured temperature, a duration that the heating module is to wait before performing a pass over the build material, and a speed at which the heating module is to travel over the build material.

First claim

The invention claimed is:

1. A method comprising:
during a first pass over a layer of build material formed on a print bed associated with an additive manufacturing apparatus, distributing print agent onto a portion of the build material and directing heat towards all of the build material using a heating module;
following the first pass over the layer of build material, measuring, using a detector, a temperature of the portion of build material to which the print agent has been applied; and
determining, using a processor, based at least in part on the measured temperature, a duration that the heating module is to wait before performing a second pass over the build material, and a speed at which the heating module is to travel over the build material during the second pass.

2. The method of claim 1 , further comprising:
controlling the heating module to wait for the determined duration before performing the second pass.

3. The method of claim 1 , further comprising:
controlling the heating module to travel over the build material at the determined speed during the second pass.

4. The method of claim 1 , wherein, determining the duration is based on at least one of:
i) a difference between the measured temperature and a target temperature;
ii) a temperature of at least a portion of a layer of build material as measured prior to a preceding pass over the build material;
iii) a determined rate of change of a temperature of build material over successive passes; and
iv) a volume of a three-dimensional object to be generated by processing the successive layers of build material.

5. The method of claim 1 , further comprising:
operating the heating module to travel at the determined speed during the second pass over the build material.

6. The method of claim 5 , wherein, during the first pass, the heating module is to increase a temperature of the build material to which print agent has been applied to a first temperature below a fusing temperature of the build material and, during the second pass, the heating module is to increase the temperature of build material to which print agent has been applied to a second, higher temperature above the fusing temperature of the build material.

7. The method of claim 5 , wherein, for all passes over a layer of build material formed on the print bed during which print agent is to be distributed onto a portion of build material, the speed at which the heating module is to travel is constant.

8. Additive manufacturing apparatus comprising:
a heating assembly to direct heat towards all of the build material in layers of build material formed on a print bed associated with the additive manufacturing apparatus during a series of passes over the print bed;
a temperature measurement element to determine a temperature of a portion of build material to which print agent has been applied during a first pass over the print bed; and
processing apparatus to calculate, based at least in part on the determined temperature:
an amount of time that the heating assembly is to wait between the first pass over the print bed and a second pass over the print bed; and
a rate of movement of the heating assembly during the second pass.

9. Additive manufacturing apparatus according to claim 8 , wherein the heating assembly forms part of, or is coupled to, a carriage for moving a print agent distributor, the print agent distributor to selectively deliver print agent during the first pass over the print bed to the portion of build material.

10. Additive manufacturing apparatus according to claim 8 , wherein the heating assembly forms part of, or is coupled to, a carriage for moving a build material distributor, the build material distributor to distribute layers of build material over the print bed.

11. Additive manufacturing apparatus according to claim 8 , wherein the heating assembly comprises a plurality of heating elements, and wherein, during a pass over the build material, a power output of the each of the heating elements remains constant.

12. Additive manufacturing apparatus according to claim 8 , wherein the processing apparatus is to:
operate the heating assembly to wait for the calculated amount of time; and
operate the heating assembly to pass over the print bed at the calculated rate.

13. A machine readable medium comprising instructions which, when executed by a processor, cause the processor to:
control a lamp assembly to pass over for a first time, each of a plurality of layers of build material formed on a print bed of an additive manufacturing apparatus so as to direct heat towards all of the build material in each layer of build material;
establish, based at least in part on a measured temperature of at least a portion of a layer of the build material to which a print agent has been applied:
a duration that the lamp assembly is to wait before beginning to pass over a layer of build material for a second time; and
a speed at which the lamp assembly is to travel over the build material during the second time.

14. A machine readable medium according to claim 13 , further comprising instructions which, when executed by a processor, cause the processor to:
control the lamp assembly to wait for the established duration before passing over a layer of build material for the second time.

15. A machine readable medium according to claim 13 , further comprising instructions which, when executed by a processor, cause the processor to:
control the lamp assembly to travel over the build material during the second time at the established speed.

Assignees

• Hewlett Packard Development Co

Inventors

• Tarradas Anna
• Vilajosana Xavier
• Mostaccio Diego Javier

Classifications

• B22F12/90

  Means for process control, e.g. cameras or sensors · CPC title

• B22F12/13

  to preheat the material · CPC title

• B22F10/30

  Process control · CPC title

• B22F10/28

  Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM] · CPC title

• B22F12/53

  Nozzles · CPC title