System and method for surface/layer structuring using an optically addressed light valve combined with optically addressed electric field modulation

Patent metadata

Field	Value
Publication number	US-2019291210-A1
Application number	US-201815927465-A
Country	US
Kind code	A1
Filing date	Mar 21, 2018
Priority date	Mar 21, 2018
Publication date	Sep 26, 2019
Grant date	—

Abstract

The present disclosure relates to a method of modifying a surface of a material, in situ, while the material is being used to at least one of form or modify a portion of a part to remove flaws layer-by-layer and improve a part from a layerwise built, or a coating. The method may involve generating first, second and third beams. The third beam may act on a surface of a material to heat a portion of the surface of the material into a flowable state to thus modify a surface characteristic of the material. The first beam may control an optically addressable light valve (OALV) which modifies an energy of the third beam. The second beam may control an optically addressable electric field modulator (OAEFM) to generate an electric field in a vicinity of the surface and to influence a movement of the portion of material while the portion of material is in the flowable state. The beams are modulated based on a sensing element feedback loop.

First claim

What is claimed is:

1 . A method of modifying a surface of a material, in situ, while the material is being used to at least one of form or modify a portion of a part or coating, the method comprising:
generating a first beam; generating a second beam; generating a third beam for acting on a surface of a material to heat a portion of the surface of the material into a flowable state to modify a surface characteristic of the material; using the first beam to control an optically addressable light valve (OALV), the OALV being controlled to modify an energy of the third beam; and using the second beam to control an optically addressable electric field modulator (OAEFM), the OAEFM being controlled to generate an electric field in a vicinity of the surface and to influence a movement of the portion of material while the portion of material is in the flowable state.

2 . The method of claim 1 , further comprising using a sensing element to sense a portion of the third beam reflected off of the surface.

3 . The method of claim 2 , further comprising using a processor to receive a feedback signal from the sensing element and to control the generation of the first and second beams.

4 . The method of claim 1 , wherein the first beam comprises an optical beam having a first wavelength, and the second beam comprises an optical beam having a second wavelength different from the first wavelength.

5 . The method of claim 4 , wherein the OALV is responsive only to the first wavelength and the OAEFM is responsive only to the second wavelength.

6 . The method of claim 1 , wherein using the first beam to control the OALV comprises using the first beam to optically address an OALV formed by a spaced apart pair of electrodes, and a photoconductor and liquid crystal positioned between the pair of electrodes, and wherein the photoconductor is tuned to a specific wavelength.

7 . The method of claim 1 , wherein using the second beam to control the OAEFM comprises using the second beam to optically address a OAEFM formed by a pair of spaced apart electrodes and a photoconductor disposed between the electrodes, the photoconductor being tuned to a specific wavelength.

8 . The method of claim 1 , further comprising directing third beam to a polarizing beam splitter, and from the polarizing beam splitter toward the OALV and the OAEFM.

9 . The method of claim 1 , wherein the first, second and third beams are used repeatedly on a plurality of distinct layers of the material during an additive manufacturing operation.

10 . The method of claim 1 , wherein the first, second and third beams are used to act on the coating to modify a surface profile of the coating.

11 . A method of modifying a surface of a material, in situ, while the material is being used to at least one of form or modify a portion of a part or coating, the method comprising:
using a first optical beam generator to generate a first beam at a first wavelength; using a second optical beam generator to generate a second beam at a second wavelength; using a third optical beam generator to generate a third beam for acting on a surface of a material to heat a portion of the surface of the material into a flowable state to at least one of ablate a portion of the material, or to modify a surface characteristic of the material, or to heat a portion of the material to achieve stress relaxation; using the first beam to control an optically addressable light valve (OALV), the OALV being controlled to modify an energy of the third beam; using the second beam to control an optically addressable electric field modulator (OAEFM), the OAEFM being controlled to generate an electric field in a vicinity of the surface of the material and to influence a movement of the portion of material while the portion of material is in the flowable state; and using a processor to control the first and second beam generators.

12 . The method of claim 11 , further comprising using the processor to receive an feedback signal to control at least one of the first, second and third optical beam generators.

13 . The method of claim 12 , further comprising using a sensing element to receive a reflected portion of the third beam, and using the sensing element to generate the feedback signal to the processor.

14 . The method of claim 11 , wherein using the first and second optical beam generators to generate the first and second beams at the first and second wavelengths comprises generating optical beams of different wavelengths.

15 . The method of claim 11 , wherein using each of the first, second and third beam generators comprises using first, second and third lasers.

16 . A system for modifying a surface of a material, in situ, while the material is being used to at least one of form or modify a portion of a part or coating, the system comprising:
a first beam generator which generates a first optical beam; a second beam generator which generates a second optical beam; a third beam generator which generates a third optical beam for acting on a surface of a material to heat a portion of the surface of the material into a flowable state to modify a surface characteristic of the material; an optically addressable light valve (OALV) controlled by the first optical beam to modify an energy of the third optical beam; and an optically addressable electric field modulator (OAEFM) controlled by the second optical beam to generate an electric field in a vicinity of the surface and to influence a movement of the portion of material while the portion of material is in the flowable state.

17 . The system of claim 16 , wherein each of the first, second and third beam generators comprises a laser.

18 . The system of claim 17 , wherein the first optical beam has a first wavelength and the second optical beam has a second wavelength different from the first wavelength.

19 . The system of claim 16 , wherein the OALV comprises:
a pair of spaced apart electrodes; a photoconductor disposed between the electrodes; and a liquid crystal disposed between the electrodes.

20 . The system of claim 16 , wherein the OAEFM comprises:
a single electrode at the input surface of a photoconductor attached to the transparent electrode.

Assignees

• L Livermore Nat Security Llc

Inventors

• Elhadj Selim
• Yoo Jae Hyuck

Classifications

• G02F1/133362

  Optically addressed liquid crystal cells (G02F1/135 takes precedence) · CPC title

• B23K26/032

  using optical means · CPC title

• B23K26/342 Primary

  Build-up welding · CPC title

• B23K26/064

  by means of optical elements, e.g. lenses, mirrors or prisms · CPC title

• B23K26/352 Primary

  for surface treatment · CPC title