Method and apparatus for forming overhanging structures in additive manufactured parts that have an improved surface roughness

Patent metadata

Field	Value
Publication number	US-2023373007-A1
Application number	US-202217664470-A
Country	US
Kind code	A1
Filing date	May 23, 2022
Priority date	May 23, 2022
Publication date	Nov 23, 2023
Grant date	—

Abstract

A three-dimensional (3D) metal object manufacturing apparatus is operated to compensate for surface deviations of overhanging features differently than for non-overhanging features. The compensation technique used for the overhanging features depends on whether an edge of the overhanging feature being formed in a next layer has curved or sharp corners.

First claim

1 - 12 . (canceled)

13 . An additive manufacturing drop ejecting apparatus comprising:
an ejector fluidly connected to a source of melted material; a digital image data generator configured to generate digital image data of an uppermost layer of an object being formed with drops of the melted material ejected by the ejector; and a controller operatively connected to the ejector and the digital image data generator, the controller being configured to:
modify machine-ready instructions used to operate the drop ejecting apparatus to form an overhanging feature of a next layer of the object using a first correction method and the generated digital image data;
modify machine-ready instructions used to operate the drop ejecting apparatus to form a non-overhanging feature of the next layer of the object using a second correction method and the generated digital image data, the second correction method being different than the first correction method; and
execute the modified machine-ready instructions to operate the drop ejecting apparatus to form the next layer of the object.

14 . The apparatus of claim 13 wherein the digital image data generator is a digital camera aligned along a Z-axis in the additive manufacturing drop ejecting apparatus that is configured to generate the digital image data of the uppermost layer of the object.

15 . The apparatus of claim 14 , the source of melted material further comprising:
a removable vessel configured to receive bulk metal and produce melted metal for ejection from the ejector.

16 . The apparatus of claim 15 , the controller being further configured to:
generate a gain map using the generated digital image data, the first correction method using a first portion of the gain map to identify changes to be made to the machine-ready instructions that form the overhanging feature and the second correction method using a second portion of the gain map to identify changes to be made to the machine-ready instructions that form the non-overhanging feature.

17 . The apparatus of claim 16 wherein the second correction method is a local correction method.

18 . The apparatus of claim 17 wherein the first correction method is an offset-based semi-local correction method.

19 . The apparatus of claim 18 , the controller is further configured to:
average values in the first portion of the gain map to identify the changes to be made to the machine-ready instructions that form the overhanging feature.

20 . The apparatus of claim 16 wherein the first correction method is a restricted semi-local correction method.

21 . The apparatus of claim 20 , the controller is further configured to:
filter portions from the first portion of the gain map before the changes are identified.

22 . The apparatus of claim 16 wherein the first correction method is a restricted semi-local correction method with trim.

23 . The apparatus of claim 22 , the controller being further configured to:
remove at least one end of the first portion of the gain map from the first portion before the changes are identified.

24 . The apparatus of claim 23 , the controller being further configured to:
remove a predetermined percentage of a length of the first portion.

Assignees

• Xerox Corp

Inventors

• Guggilapu Priyaankadevi
• Paulson Benjamin
• Jayabal Dinesh Krishna Kumar
• Ladd Collin A
• Schweid Stuart A

Classifications

• B22F10/385 Primary

  Overhang structures · CPC title

• B22F10/22 Primary

  Direct deposition of molten metal · CPC title

• B22F10/85

  for controlling or regulating additive manufacturing processes · CPC title

• B22F12/53

  Nozzles · CPC title

• B22F12/90 Primary

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