System and methods for printing defect detection

Patent metadata

Field	Value
Publication number	US-2025117918-A1
Application number	US-202418659043-A
Country	US
Kind code	A1
Filing date	May 9, 2024
Priority date	Dec 9, 2019
Publication date	Apr 10, 2025
Grant date	—

Abstract

An additive manufacturing method includes depositing a first amount of metal powder onto a powder bed of a printing system, spreading the first amount of metal powder across the powder bed to form a first layer, and depositing a first amount of binder material on the first layer. The additive manufacturing method also includes exposing the first layer to a first lighting condition, imaging the first layer under the first lighting condition to generate a first image, analyzing the first image of the first layer, and determining whether to adjust at least one printing parameter based on the analyzing.

First claim

What is claimed:

1 . A method of detecting and ameliorating defects during metal additive manufacturing, comprising the steps of:
spreading a metal powder on a powder bed of a metal additive manufacturing system and depositing a predetermined pattern of binder to the metal powder to form a layer of a green part; illuminating the layer of the green part with a first light source; capturing via an imaging device a first image of the illuminated layer of the green part; analyzing the first image and identifying a first defect in the layer of the green part; and adjusting at least one printing parameter in response to identifying the first defect to ameliorate the first defect.

2 . The method of claim 1 wherein an axis of the first light source is angled with respect to the powder bed by 1 degree to 10 degrees.

3 . The method of claim 1 wherein an axis of the first light source is angled with respect to the powder bed by 70 degree to 110 degrees.

4 . The method of claim 1 wherein the defect is one of a blister, a divot, beading, a smear and a jet-out condition.

5 . The method of claim 1 wherein the step of analyzing includes identifying at least one shadow in the first image.

6 . The method of claim 1 , wherein the step of analyzing includes identifying at least one region that is brighter than an average brightness of the layer of the green part.

7 . The method of claim 1 wherein the step of analyzing includes detecting a bright spot and an associated shadow.

8 . The method of claim 1 wherein step of analyzing includes detecting at least one of a region of missing binder material, a bright region and a shadow in the first image.

9 . The method of claim 1 wherein the printing parameter is one of a vapor deposition rate, a binder deposition rate, and a negative feature pattern.

10 . The method of claim 1 , further comprising the steps of:
illuminating the layer of the green part with a second light source; capturing via a second imaging device a second image of the illuminated layer of the green part; analyzing the second image and identifying a second defect in the layer of the green part; and adjusting at least one printing parameter in response to identifying the second defect to ameliorate the second defect.

11 . A method of detecting defects during metal additive manufacturing, comprising the steps of:
spreading a metal powder on a powder bed of a metal additive manufacturing system and depositing a predetermined pattern of binder to the metal powder to form a layer of a green part; generating a first illumination condition and capturing a first image of the illuminated layer of the green part with a first imaging device; generating a second illumination condition and capturing a second image of the illuminated layer of the green part with a second imaging device; and comparing the first image and second image to at least one of each other, a design file and a third image and identifying a first defect in the layer of the green part.

12 . The method of claim 11 wherein an axis of the first light source is angled with respect to the powder bed by 1 degree to 10 degrees.

13 . The method of claim 12 wherein an axis of the second light source is angled with respect to the powder bed by 70 degree to 110 degrees.

14 . The method of claim 11 wherein the defect is one of a blister, a divot, a smear, beading and a jet-out condition.

15 . The method of claim 11 wherein the step of analyzing includes identifying at least one shadow in one of the first image and second image.

15 . The method of claim 11 , wherein the step of analyzing includes identifying at least one region that is brighter than an average brightness of the layer of the green part.

16 . The method of claim 11 wherein the step of analyzing includes detecting a bright spot and an associated shadow.

17 . The method of claim 11 wherein step of analyzing includes detecting at least one of a region of missing binder material, a bright region and a shadow in one of the first image and the second image.

18 . The method of claim 11 wherein the printing parameter is one of a vapor deposition rate, a binder deposition rate, and a negative feature pattern.

19 . The method of claim 11 wherein the third image is an image of a preceding layer in the green part.

20 . A method of identifying and clearing clogged jetting orifices in a binder jetting metal additive manufacturing system, comprising the steps of:
spreading from a printhead a metal powder on a powder bed of a metal additive manufacturing system and depositing a predetermined pattern of binder to the metal powder to form a layer of a green part; illuminating the layer of the green part with a high angle light source; capturing an image of the illuminated layer of the green part with an imaging device; identifying areas of unbound powder according to the brightness an amount of reflected light; comparing the areas of unbound powder to a design file and identifying a defect indicating a jet-out condition; and subjecting the printhead to a maintenance cycle.

Assignees

• Desktop Metal Inc

Inventors

• Hudelson George
• Mccambridge Matthew
• Dec Jake
• Legendre Alexander

Classifications

• G06T2207/30144

  Printing quality · CPC title

• G06T7/001

  using an image reference approach · CPC title

• B22F10/85

  for controlling or regulating additive manufacturing processes · CPC title

• B22F1/10

  Metallic powder containing lubricating or binding agents; Metallic powder containing organic material · CPC title

• B22F2203/00

  Controlling · CPC title