Method and apparatus for real time, in situ sensing and characterization of roughness, geometrical shapes, geometrical structures, composition, defects, and temperature in three-dimensional manufacturing systems

Patent metadata

Field	Value
Publication number	US-11465240-B2
Application number	US-201916378485-A
Country	US
Kind code	B2
Filing date	Apr 8, 2019
Priority date	Apr 8, 2019
Publication date	Oct 11, 2022
Grant date	Oct 11, 2022

Abstract

Methods and apparatuses for manufacturing are disclosed, including (a) providing an apparatus having: a laser; scanner; powder injection system; powder spreading system; dichroic filter; imager-and-processor; and computer; (b) programming the computer with specifications of a sample; (c) using the computer to set initial parameters based on the sample specifications; (d) adjusting a stage to position the sample; (e) focusing and scanning electromagnetic radiation onto the sample while powder is concurrently injected onto the sample in order to deposit a layer; (f) capturing two-dimensional images of the sample and probing the sample to determine whether the deposited layer was manufactured per the specifications; (g) use the computer to adjust the three-dimensional manufacturing parameters based on the determination made in step (f) prior to additively manufacturing a subsequent layer or making repairs; and (h) repeating steps (d), (e), (f), and (g) until the manufacture is complete. Other embodiments are described and claimed.

First claim

The invention claimed is:

1. A method for real time, in situ sensing and characterization of roughness, geometrical shapes, geometrical structures, composition, defects, and temperature in three-dimensional manufacturing comprising:
(a) providing an apparatus having:
one or more lasers configured to generate electromagnetic radiation;
an autofocusing scanner configured to receive the electromagnetic radiation from the one or more lasers and to focus and scan the electromagnetic radiation onto a stage where a sample is three-dimensionally manufactured;
a powder injection system configured to inject one or more powders toward the stage in the vicinity of the focused electromagnetic radiation;
a powder spreading system configured to spread one or more powders to form a powder layer onto a previously processed layer of the sample;
a dichroic filter positioned between the autofocusing scanner and the stage;
an imager and processor focused through the dichroic filter and onto the sample, wherein the imager and processor are configured to monitor structure, temperature, shape, defects, cracks, and roughness of the sample;
a non-destructive probing inspection system configured to monitor the composition of the sample; and
one or more computers coupled to the one or more lasers, the autofocusing scanner, the stage, the powder injection system, the powder spreading system, the imager and processor, and the non-destructive probing inspection system and configured to monitor in about real-time one or more three-dimensional manufacturing parameters and provide control feedback to the apparatus;

(b) programming the one or more computers with structural and material specifications of the sample;
(c) using the one or more computers to set initial laser, scan parameters, and powder injection and/or spreading parameters based on the structural and material specifications of the sample programmed into the one or more computers;
(d) adjusting the stage in order to position the sample within the scanning and focus range of the electromagnetic radiation;
(e) using the autofocusing scanner to focus and scan the electromagnetic radiation onto the sample while powder is concurrently injected by the powder injection system and/or spreading system onto the sample in order to deposit a layer onto the sample;
(f) use the imager and processor to capture two-dimensional images of the sample and the non-destructive probing inspection system to probe the sample to make a determination of whether or not the deposited layer was manufactured per the structural and material specifications of the sample;
(g) using the one or more computers to adjust the one or more three-dimensional manufacturing parameters based on the determination made in step (f) prior to either additively manufacturing a subsequent layer onto the sample or making repairs to the deposited layer; and
(h) repeating steps (d), (e), (f), and (g) until the three-dimensional manufacture of the sample is complete.

2. The method of claim 1 , wherein the method further comprises using the imager and processor and the non-destructive probing inspection system to record a final quality characterization of the sample.

3. The method of claim 1 , wherein making a determination of whether or not the deposited layer was manufactured per the structural and material specifications of the sample comprises:
extracting structure and roughness data of the surface of the sample from the grey level of the captured two-dimensional images of the sample illuminated with light at a known angle relative to the surface of the sample;
using the structure and roughness data of the surface of the sample to calculate emissivity; and
calculating the temperature of the sample by calibrating the captured two-dimensional images with the calculated emissivity.

4. The method of claim 3 , wherein the structure and roughness data comprises stress and fatigue information of the sample.

5. The method of claim 1 , wherein the imager and processor comprises a thermal IR imager and a high resolution visible camera.

6. The method of claim 5 , wherein the thermal IR imager operates within a spectral region of 3-14 μm, and the high resolution visible camera has at least 10 megapixels.

7. The method of claim 1 , wherein the one or more three-dimensional manufacturing parameters comprises laser power, pulse width, energy, pulse repetition rate, beam shape, temporal format, scanning speed, hatching space, scanning strategy/pattern, and/or powder thickness.

8. The method of claim 1 , wherein the non-destructive probing inspection system comprises a collinear LIBS system to detect composition and temperature of melting points.

9. The method of claim 1 , wherein the non-destructive probing inspection system comprises a LIPI system to detect subsurface defects and surface roughness.

10. The method of claim 1 , wherein one of the one or more lasers comprises a CW or pulsed fiber laser and an acousto-optic modulator configured to control temporal format.

11. The method of claim 1 , wherein the electromagnetic radiation comprises a wavelength between about 1030 nm to about 1100 nm, a pulse repetition rate between about 100 kHz and about 1 GHz, a pulse width between about 750 fs to about 10 ns, a pulse energy having a maximum of 500 μJ, and an average power of about 1 kW.

12. An apparatus for real time, in situ sensing and characterization of roughness, geometrical shapes, geometrical structures, composition, defects, and temperature in three-dimensional manufacturing comprising:
one or more lasers configured to generate electromagnetic radiation;
an autofocusing scanner configured to receive the electromagnetic radiation from the one or more lasers and to focus and scan the electromagnetic radiation onto a stage where a sample is three-dimensionally manufactured;
a powder injection system configured to inject one or more powders toward the stage in the vicinity of the focused electromagnetic radiation;
a powder spreading system configured to spread one or more powders to form a powder layer onto a previously processed layer of the sample;
a dichroic filter positioned between the autofocusing scanner and the stage;
an imager and processor focused through the dichroic filter and onto the sample, wherein the imager and processor are configured to monitor structure, temperature, shape, defects, cracks, and roughness of the sample;
a non-destructive probing inspection system configured to monitor the composition of the sample; and
one or more computers coupled to the one or more lasers, the autofocusing scanner, the stage, the powder injection system, the powder spreading system, the imager and processor, and the non-destructive probing inspection system and configured to monitor in about real-time one or more three-dimensional manufacturing parameters and provide control feedback to the apparatus.

13. The apparatus of claim 12 , wherein the one or more computers configured to monitor in about real-time one or more three-dimensional manufacturing parameters comprises:
processing and analyzing in about real-time data gathered from the imager and processor and the non-destructive probing system to determine the temperature of the sample by extracting structure and roughness data of the surface of the sample from the grey level of captured two-dimensional images of the sample illuminated with light at a known angle relative to the surface of the sample;
using the structure and roughness data of the surface of the sample to calculate emissivity; and
using the calculated emissivity to calibrate the two-dimensional images captured by the imager and processor.

Assignees

• Liu Jian
• Polaronyx Inc

Inventors

• Liu Jian

Classifications

• G01N21/1702 Primary

  with opto-acoustic detection, e.g. for gases or analysing solids · CPC title

• B23K26/354 Primary

  by melting · CPC title

• B22F12/49

  Scanners · CPC title

• B22F12/45

  Two or more · CPC title

• B22F12/43

  pulsed; frequency modulated · CPC title