Method for rapid development of additive manufacturing parameter set

Patent metadata

Field	Value
Publication number	US-11633790-B2
Application number	US-202017777598-A
Country	US
Kind code	B2
Filing date	Nov 18, 2020
Priority date	Nov 18, 2019
Publication date	Apr 25, 2023
Grant date	Apr 25, 2023

Abstract

An apparatus includes a control system that defines a test part having multiple features of multiple feature types. The control system controls an additive manufacturing (AM) machine to print multiple copies of the test part, with each copy being printed according to a respective set of values used as printing parameters. A measurement system obtains a computed tomography (CT) image of each of the copies of the test part. An analysis system, for each of the plurality of feature types, analyzes the CT images to identify a selected set of values for the printing parameters. The analysis system identifies a portion of the CT image related to a first feature and assesses its density based on an average grayscale value. The AM machine is then controlled to print production parts according to, for each feature type of the production parts, the selected set of values for the printing parameters.

First claim

What is claimed is:

1. An apparatus comprising:
a control system configured to:
define a test part having a plurality of features of a plurality of feature types, wherein the plurality of features includes a first feature that is a bulk type and
control an additive manufacturing (AM) machine to print multiple copies of the test part,
wherein the AM machine operates according to a plurality of printing parameters,
wherein the control system is configured to generate, for each of the multiple copies, a set of values for the plurality of printing parameters, and
wherein the control system is configured to control the AM machine to print each of the multiple copies according to the respective set of values for the plurality of printing parameters;

a measurement system configured to obtain a computed tomography (CT) image of each of the copies of the test part; and
an analysis system configured to, for each of the plurality of feature types, analyze the CT images to identify a selected set of values for the plurality of printing parameters,
wherein the analysis system is configured to identify a portion of the CT image related to the first feature and assess density of the first feature based on an average grayscale value of the portion of the CT image and
wherein the control system is configured to control the AM machine to print production parts according to, for each feature type of the production parts, the selected set of values for the plurality of printing parameters.

2. The apparatus of claim 1 wherein the control system is configured to control the AM machine to print the multiple copies of the test part in response to a new printing material being introduced to the AM machine.

3. The apparatus of claim 2 wherein the printing material is a powder.

4. The apparatus of claim 3 wherein the AM machine uses selective laser sintering (SLS).

5. The apparatus of claim 1 wherein, for each of the multiple copies, the set of values of the plurality of printing parameters is distinct from all others of the multiple copies.

6. The apparatus of claim 1 wherein the control system is configured to control the AM machine to print a second batch of multiple copies of the test part in response to, for at least one of the feature types, the selected set of values for the plurality of printing parameters resulting in at least one feature of merit falling short of a threshold.

7. The apparatus of claim 1 further comprising a sample holder configured to hold a first part of the multiple copies, wherein the sample holder includes at least one calibration standard having known density values, and wherein the analysis system is configured to calibrate values of the CT image according to a relationship between measured values of the at least one calibration standard and the known density values.

8. The apparatus of claim 1 wherein the plurality of feature types includes the bulk type, a vertical fin type, a hole type, and a rod type.

9. The apparatus of claim 8 wherein the plurality of feature types includes the bulk type, the vertical fin type, a horizontal cylindrical hole type, a vertical cylindrical hole type, a horizontal rod type, and a vertical rod type.

10. The apparatus of claim 1 wherein:
the plurality of feature types includes the bulk type and an inclined fin type;
features having the inclined fin type are removed from the multiple copies; and
the features having the inclined fin type are measured using at least one of an optical microscope and a coordinate measuring machine.

11. The apparatus of claim 1 wherein the analysis system is configured to align the CT image of each of the copies of the test part with a test part design to identify each of the plurality of features on each of the copies of the test part.

12. The apparatus of claim 1 wherein:
the analysis system is configured to identify each of the copies of the test part by reading a unique identifier on the test part and
the unique identifiers for the copies of the test parts are created as part of printing by the AM machine.

13. The apparatus of claim 12 wherein the analysis system is configured to read the unique identifier using optical character recognition (OCR).

14. The apparatus of claim 12 wherein the unique identifier includes at least one of a one-dimensional barcode and a two-dimensional barcode.

15. The apparatus of claim 1 wherein the plurality of feature types includes a periphery defined within an outer surface of the test part and a predetermined distance from the outer surface.

16. The apparatus of claim 1 wherein the analysis system is configured to analyze a microstructure of each of the copies of the test part using at least one of X-ray diffraction imaging, X-ray contrast tomography, scanning electron microscope (SEM)-based electron backscatter diffraction (EBSD), and optical (light) microscopy.

17. A method comprising:
defining a test part having a plurality of features of a plurality of feature types, wherein the plurality of features includes a first feature that is a bulk type;
controlling an additive manufacturing (AM) machine to print multiple copies of the test part, wherein the AM machine operates according to a plurality of printing parameters, wherein the controlling includes:
for each of the multiple copies, generating a set of values for the plurality of printing parameters and
controlling the AM machine to print each of the multiple copies according to the respective set of values for the plurality of printing parameters;

obtaining a computed tomography (CT) image of each of the copies of the test part;
for each of the plurality of feature types, analyzing the CT images to identify a selected set of values for the plurality of printing parameters, wherein the analyzing includes:
identifying a portion of the CT image related to the first feature and
assessing density of the first feature based on an average grayscale value of the portion of the CT image; and

controlling the AM machine to print production parts according to, for each feature type of the production parts, the selected set of values for the plurality of printing parameters.

18. The method of claim 17 further comprising controlling the AM machine to print the multiple copies of the test part in response to a new printing material being introduced to the AM machine.

19. The method of claim 18 wherein the printing material is a powder.

20. The method of claim 19 wherein the AM machine uses selective laser sintering (SLS).

21. The method of claim 17 wherein, for each of the multiple copies, the set of values of the plurality of printing parameters is distinct from all others of the multiple copies.

22. The method of claim 17 further comprising controlling the AM machine to print a second batch of multiple copies of the test part in response to, for at least one of the feature types, the selected set of values for the plurality of printing parameters resulting in at least one feature of merit falling short of a threshold.

23. The method of claim 17 further comprising calibrating values of the CT image according to a relationship between measured values of at least one calibration standard and known density values of the at least one calibration standard.

24. The method of claim 17 wherein the plurality of feature types includes the bulk type, a vertical fin type, a hole type, and a rod type.

25. The method of claim 24 where

Assignees

• Carl Zeiss Ind Metrology Llc
• Ut Battelle Llc

Inventors

• Bhattad Pradeep
• Brackman Paul
• Frederick Curtis
• Bauza Marcin B
• Santos Edson Costa
• Dehoff Ryan
• Plotkowski Alex
• Lisovich Aleksandr
• Tenboer Jason James

Classifications

• G06T12/10

  Image preprocessing, e.g. calibration, positioning of sources or scatter correction · CPC title

• G06V10/44

  Local feature extraction by analysis of parts of the pattern, e.g. by detecting edges, contours, loops, corners, strokes or intersections; Connectivity analysis, e.g. of connected components · CPC title

• G06V30/18019

  by matching or filtering · CPC title

• B22F12/90

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

• B33Y10/00

  Processes of additive manufacturing · CPC title