System and Method for High Power Diode Based Additive Manufacturing

• US 20140252687A1
• Filed: 03/05/2013
• Published: 09/11/2014
• Est. Priority Date: 03/05/2013
• Status: Active Grant

• Current Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Original Assignee: Lawrence Livermore National Security LLC (Government of the United States of America)
• Inventors: FARMER, Joseph C., EL-DASHER, Bassem S., BAYRAMIAN, Andrew, DEMUTH, James A., TORRES, Sharon G.
• Granted Patent: US 9,308,583 B2
• Time in Patent Office: Days
• US Class Current: 264/497
• CPC Class Codes: B22F 10/20 Direct sintering or melting
• CPC Class Codes: B22F 10/28 Powder bed fusion, e.g. selective laser melting [SLM] or electron beam melting [EBM]
• CPC Class Codes: B22F 10/30 Process control
• CPC Class Codes: B22F 10/36 of energy beam parameters
• CPC Class Codes: B22F 12/43 pulsed; frequency modulated
• CPC Class Codes: B22F 12/44 characterised by the configuration of the radiation means
• CPC Class Codes: B22F 12/55 Two or more means for feeding material
• CPC Class Codes: B23K 26/042 Automatically aligning the laser beam
• CPC Class Codes: B23K 26/0622 by shaping pulses
• CPC Class Codes: B23K 26/0643 comprising mirrors
• CPC Class Codes: B23K 26/066 by using masks
• CPC Class Codes: B23K 26/144 the fluid stream containing particles, e.g. powder
• CPC Class Codes: B23K 26/342 Build-up welding
• CPC Class Codes: B29C 64/153 using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: C22C 32/0026 Matrix based on Ni, Co, Cr or alloys thereof
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

A system is disclosed for performing an Additive Manufacturing (AM) fabrication process on a powdered material forming a substrate. The system may make use of a diode array for generating an optical signal sufficient to melt a powdered material of the substrate. A mask may be used for preventing a first predetermined portion of the optical signal from reaching the substrate, while allowing a second predetermined portion to reach the substrate. At least one processor may be used for controlling an output of the diode array.

Claims

1. A system for performing an Additive Manufacturing (AM) fabrication process on a powdered material forming a substrate, the system comprising:

a diode array for generating an optical signal sufficient to melt or sinter a powdered material of the substrate;

a mask for preventing a first predetermined portion of the optical signal from reaching the substrate, while allowing a second predetermined portion to reach the substrate; and

at least one processor controlling an output of the diode array.

2. The system of claim 1, wherein the diode array comprises a plurality of diode bars.

3. The system of claim 2, wherein the diode array is configured to provide a power density of at least about 10 kW/cm² at a two percent duty cycle.

4. The system of claim 1, wherein the mask comprises:

a liquid crystal module; and

a polarizing element, the polarizing element operating to reflect portions of the optical signal that have been acted on by the liquid crystal module away from the substrate.

5. The system of claim 4, wherein the liquid crystal module comprises a computer controllable liquid crystal module configured to be digitally controlled by the processor.

6. The system of claim 4, wherein the polarizing element comprises a polarizing mirror.

7. A system for performing an Additive Manufacturing (AM) fabrication process on a powdered material forming a substrate, the system comprising:

a diode array for generating a pulsed optical signal sufficient in optical intensity to melt a powdered material of the substrate;

a mask interposed between the diode array and the substrate for preventing a first predetermined portion of the pulsed optical signal from reaching the substrate, while allowing a second predetermined portion to reach the substrate, the mask being configured to be controlled and addressable by a processor to electronically enable selected subportions of the substrate to be masked off; and

a processor for electronically controlling the mask.

8. The system of claim 7, wherein:

the diode array is configured to be electronically controlled; and

wherein the processor is configured to electronically control the diode array to control on and off operation of the diode array.

9. The system of claim 7, wherein the mask is configured to be digitally controlled by the processor.

10. The system of claim 7, wherein the mask comprises a liquid crystal module that is electronically addressable by the processor to prevent selected areas of the substrate from being exposed to the pulsed optical signal from the diode array.

11. The system of claim 7, wherein the mask comprises a polarizing element.

12. The system of claim 11, wherein the polarizing element comprises a polarizing mirror disposed at a 45 degree angle from a plane that the pulsed optical signal from the diode array travels in.

13. The system of claim 7, wherein the diode array is configured to generate a power output of at least about 10 kW/cm² at a duty cycle of about two percent.

14. A method for performing Additive Manufacturing (AM) comprising:

irradiating a powdered layer of a substrate using a pulsed optical signal sufficient, to irradiate at least a substantial portion of an entire two dimensional area within which the substrate is positioned;

using a mask to selectively block a first subportion of the pulsed optical signal from reaching the first layer of the substrate;

placing a second layer of powdered material over the first layer; and

irradiating the second layer using the pulsed optical signal while using the mask to selectively block a second subportion of the pulsed optical signal from reaching the second layer of the substrate.

15. The method of claim 14, wherein the irradiating a powdered layer of a substrate using a pulsed optical signal comprises using a pulsed diode array to generate the pulsed optical signal.

16. The method of claim 15, wherein the using the pulsed diode array comprises using a pulsed diode array configured to generate a power density of at least about 10 kW/cm².

17. The method of claim 14, wherein the using a mask to selectively block a first subportion of the pulsed optical signal comprises using a digitally electronically addressable mask to selectively block the first subportion of the pulsed optical signal.

18. The method of claim 17, wherein the using a digitally electronically addressable mask comprises using a liquid crystal module and a polarizing element.

19. The method of claim 17, further comprising using a computer to control the digitally electronically addressable mask.

20. The method of claim 15, further comprising using a computer to control the pulsed diode array.

21. The method of claim 14, further comprising using a movable, electronically addressable spray source to deposit at least two different material types to form at least one of the first and second layers.

22. The method of claim 21, further comprising controlling the mask in accordance with the at least two different material types being irradiated.