Occulting device for optical system in additive manufacturing systems

Patent metadata

Field	Value
Publication number	US-12358075-B2
Application number	US-202117533664-A
Country	US
Kind code	B2
Filing date	Nov 23, 2021
Priority date	Nov 24, 2020
Publication date	Jul 15, 2025
Grant date	Jul 15, 2025

Abstract

An additive manufacturing system may include an energy delivery device configured to deliver energy to a component to form a melt pool at least partially surrounded by a cooling region; and an optical system comprising: an imaging device; and an occulting device, wherein the occulting device is configured to occult at least part of thermal emissions produced by the energy and the melt pool and transmit at least some thermal emissions produced by the cooling region.

First claim

The invention claimed is:

1. An additive manufacturing system comprising:
an energy delivery device configured to deliver energy to a component to form a melt pool at least partially surrounded by a cooling region; and
an optical system comprising:
an imaging device; and
an occulting device, wherein the occulting device is configured to:
occult at least part of thermal emissions with a wavelength of interest from a selected region to reduce the intensity of the thermal emissions from the selected region, wherein the thermal emissions from the selected region are produced by the energy and the melt pool, and
transmit at least some thermal emissions with the wavelength of interest produced by the cooling region at least partially surrounding the melt pool, wherein the wavelength of the thermal emissions from the selected region that are occulted by the occulting device is the same as the wavelength of the thermal emissions produced by the cooling region that are transmitted past the occulting device,

wherein the imaging device is configured to detect and image the thermal emissions of the cooling region that are transmitted past the occulting device, wherein the detection of the thermal emissions of the cooling regions transmitted past the occulting device is enabled by the occulting of the thermal emissions from the selected region, wherein the thermal emissions detected and imaged by the imaging device allow for measurement of temperature within the cooling region when a material is solidifying within the cooling region, wherein the additive manufacturing system is configured to predict a microstructure of the material when solidified based on the measured temperature, and wherein the occulting device prevents the imaging device from imaging thermal emissions of the melt pool by the occulting of the thermal emissions from the selected region.

2. The additive manufacturing system of claim 1 , wherein the occulting device comprises a rigid diameter occulting disk with a central region that is opaque to the thermal emission with the one or more wavelengths of interest and an annular region that is transparent to the thermal emissions with the one or more wavelengths of interest.

3. The additive manufacturing system of claim 2 , wherein the occulting device comprises an apodizing reflective neutral density filter with a gradient in opacity to the thermal emissions with the one or more wavelengths of interest between the central region and the annular region.

4. The additive manufacturing system of claim 1 , wherein the occulting device comprises at least one of a rigid diameter occulting disk or an apodizing reflective neutral density filter configured to be translated along an optical axis of the optical system.

5. The additive manufacturing system of claim 1 , wherein the occulting device comprises a viscous opaque liquid between two substrates.

6. The additive manufacturing system of claim 1 , wherein the occulting device comprises a digital mirror device.

7. The additive manufacturing system of claim 1 , further comprising a computing device configured to control the energy delivery device and the occulting device, and wherein the computing device is configured to predict the microstructure of the material when solidified based on the measured temperature.

8. The additive manufacturing system of claim 1 , further comprising a powder delivery device configured to deliver a powder to the melt pool.

9. The additive manufacturing system of claim 7 , wherein the occulting device comprises a dynamic occulting device, and wherein the computing device is configured to control the dynamic occulting device to occult the selected region based on an intensity profile detected by the imaging device to achieve a desired intensity profile.

10. The additive manufacturing system of claim 1 , wherein the measurement of the temperature within the cooling region from the thermal emissions imaged by the imaging device is more accurate with the occulting of the at least part of the thermal emissions by the occulting device compared to a measurement without the occulting of the at least part of the thermal emissions by the occulting device.

11. The additive manufacturing system of claim 1 , wherein the occulting device comprises a dynamic occulting device, the dynamic occulting device including a viscous opaque liquid between a first substrate and a second substrate, wherein the computing device is configured to control a diameter of the viscous opaque liquid to occult the at least part of thermal emissions from the selected region and transmit the at least some thermal emission produced by the cooling region, wherein the computing device controls the diameter of the viscous opaque liquid by controlling a distance between the first substrate and the second substrate.

12. A method comprising:
controlling, by a computing device, an energy delivery device to deliver energy to a component to form a melt pool at least partially surrounded by a cooling region;
controlling, by the computing device, an optical system to measure thermal emissions emitted by the cooling region, wherein the optical system comprises:
an imaging device; and
an occulting device, wherein the occulting device is configured to:
occult at least part of thermal emissions with a wavelength of interest from a selected region to reduce the intensity of the thermal emissions from the selected region, wherein the thermal emissions from the selected region are produced by the energy and the melt pool, and
transmit at least some thermal emissions with the wavelength of interest produced by the cooling region at least partially surrounding the melt pool, wherein the wavelength of the thermal emissions from the selected region that are occulted by the occulting device is the same as the wavelength of the thermal emissions produced by the cooling region that are transmitted past the occulting device,

wherein the imaging device is configured to detect and image the thermal emissions of the cooling region that are transmitted past the occulting device, wherein the detection of the thermal emissions of the cooling regions transmitted past the occulting device is enabled by the occulting of the thermal emissions from the selected region, wherein the thermal emissions detected and imaged by the imaging device allow for measurement of temperature within the cooling region when a material is solidifying within the cooling region, wherein the occulting device prevents the imaging device from imaging thermal emissions of the melt pool by the occulting of the thermal emissions from the selected region; and
predicting, via the computing device, a microstructure of the material when solidified based on the measured temperature.

13. The method of claim 12 , wherein the occulting device comprises a rigid diameter occulting disk with a central region that is opaque to the thermal emission with the one or more wavelengths of interest and an annular region that is transparent to the thermal emissions with the one or more wavelengths of interest.

14. The method of claim 13 , wherein the occulting device comprises an apodizing reflective neutral density filter with a gradient in opacity to the thermal emissions with the one or more wavelengths of interest between the central region and the annular region.

15. The method of claim 12 , wherein the occulting device comprises at least one of a rigid diameter occulting disk or an apodizing reflective neutral density filter configured to be translated along an optical axis of the optical system, and wherein the method further comprises:
controlling, by

Assignees

• Rolls Royce Corp

Inventors

• Thomas Baily
• Nelson Scott
• Nassar Abdalla R
• Grubbs John

Classifications

• G02B5/205

  Neutral density filters · CPC title

• B23K26/034

  Observing the temperature of the workpiece · CPC title

• B22F10/368

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

• B22F10/28

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

• B22F12/40

  Radiation means · CPC title