Device For In-Situ Fabrication Process Monitoring And Feedback Control Of An Electron Beam Additive Manufacturing Process

Patent metadata

Field	Value
Publication number	US-2020215810-A1
Application number	US-201816615694-A
Country	US
Kind code	A1
Filing date	May 21, 2018
Priority date	May 22, 2017
Publication date	Jul 9, 2020
Grant date	—

Abstract

A High Energy Beam Processing (HEBP) system provides feedback signal monitoring and feedback control for the improvement of process repeatability and three-dimensional (3D) printed part quality. Signals reflecting process parameters and the quality of the fabricated parts are analyzed by monitoring feedback signals from artifact sources with a process controller which adjusts process parameters. In this manner, fabricated parts are produced more accurately and consistently from powder feedstock by compensating for process variation in response to feedback signals.

First claim

1 . A monitoring and feedback device for use in conjunction with an electron beam generation apparatus in assessing and providing feedback associated with a processing area and a build structure formed from at least a portion of a powder bed on a substrate within the processing area using the electron beam generation apparatus, comprising:
an electronic imaging device including a first plate configured to be electrically insulated from the electron beam generation apparatus and including a feedback signal-capturing surface that electrically conducts an electronic imaging electrical signal upon impingement of impinging electrons emitted from the build structure, the first plate extending either one of or both over and around the processing area; and a monitoring controller configured for receiving and interpreting, by one or more processors, any one or any combination of the following: (i) the electronic imaging electrical signal electrically conducted by the feedback signal-capturing surface to assess the quality of the deposition of the powder bed within the processing area, and (ii) the electronic imaging electrical signal electrically conducted by the feedback signal-capturing surface to assess the quality of a solidified surface of the build structure after sintering or melting a portion of the powder bed within the processing area, the monitoring controller being further configured for transmitting, by one or more processors, one or more instructional electrical signals corresponding to the following: (i) first instructions based on the assessed quality of the deposition of the powder bed when the monitoring controller assesses the quality of the deposition of the powder bed within the processing area, and (ii) second instructions based on the assessed quality of a solidified surface of the build structure after sintering or melting a portion of the powder bed when the monitoring controller assesses the quality of the solidified surface of the build structure after sintering or melting a portion of the powder bed.

2 . The device of claim 1 , wherein the electronic imaging device further includes a second plate electrically insulated from the first plate, the second plate providing an electrical noise-filtering surface confronting the first plate.

3 . The device of claim 1 , wherein the first plate is configured to extend over the processing area in a direction non-orthogonal and nonparallel to the substrate.

4 . The device of claim 1 , wherein the electronic imaging device further comprises a frame having a base defining a beam opening for receiving the electron beam upon deflection thereof and a base opening opposite the beam opening and configured to overlay the substrate.

5 . The device of claim 1 , wherein the electronic imaging device is a temperature measurement and electronic imaging device that further includes a thermal energy sensing device electrically connected with the first plate, the thermal energy sensing device being configured for electrically conducting a thermal energy sensing electrical signal upon receipt of thermal radiation emitted from the build structure, wherein the monitoring controller is configured for receiving and interpreting, by one or more processors, the thermal energy sensing electrical signal electrically conducted by the thermal energy sensing device to assess the temperature of the processing area, and wherein the monitoring controller is further configured for transmitting, by one or more processors, an instructional electrical signal corresponding to thermal energy instructions based on the assessed temperature of the powder bed within the processing area.

6 . The device of claim 5 , wherein the thermal energy sensing device is a thermocouple, further comprising:
a first electrical resistor electrically connected to the first plate; a second electrical resistor electrically connected to the second plate; a thermocouple amplifier electrically connected to the thermocouple, the thermocouple amplifier providing a feedback electron signal corresponding to the thermal energy sensing electrical signal; an instrumentation amplifier electrically connected to each of the first and the second resistors, the instrumentation amplifier providing a suitable signal-to-noise ratio to a feedback electron signal corresponding to the electronic imaging electrical signal; and a suitable data logger for sampling and suitably conditioning the electronic imaging and the thermal energy sensing electrical signals.

7 . The device of claim 1 , further comprising an electromagnetic radiation detection device configured to be mounted in a housing providing vapor protection and thermal regulation, wherein the electromagnetic radiation detection device is configured for placement at least partially within a vacuum chamber and for electrically conducting a radiation detection electrical signal upon the detection of electromagnetic radiation emitted from the build structure, wherein the monitoring controller is configured for receiving and interpreting, by one or more processors, the radiation detection electrical signal electrically conducted by the electromagnetic radiation detection device to assess the chemical composition within the processing area, and wherein the monitoring controller is further configured for transmitting, by one or more processors, an instructional electrical signal corresponding to detected radiation instructions based on the assessed chemical composition within the processing area.

8 . The device of claim 7 , wherein the electromagnetic radiation detection device is an energy dispersive x-ray detection device, and wherein the electromagnetic radiation is provided by x-rays.

9 . The device of claim 7 , wherein the radiation detection electrical signal is convertible into spectra.

10 . The device of claim 7 , wherein the electronic imaging device is a temperature measurement and electronic imaging device that further includes (iii) a thermal energy sensing device electrically connected with the first plate, the thermal energy sensing device being configured for electrically conducting a thermal energy sensing electrical signal upon receipt of thermal radiation emitted from the build structure, wherein the monitoring controller is configured for receiving and interpreting, by one or more processors, the thermal energy sensing electrical signal electrically conducted by the thermal energy sensing device to assess the temperature of the processing area, and wherein the monitoring controller is further configured for transmitting, by one or more processors, an instructional electrical signal corresponding to thermal energy instructions based on the assessed temperature of the powder bed within the processing area, and wherein one or some combination of the electronic imaging electrical signal, the thermal energy sensing electrical signal, and the radiation detection electrical signal are indicate a respective one or some combination of the following:
(i) a quality of the powder, (ii) a quality of the powder bed, (iii) a temperature stability of a liquid melt zone in the powder bed, (iv) topographical characteristics of the liquid melt zone, (v) topographical characteristics of a solidified melted surface, (vi) any geometric deviation of the solidified melted surface when compared to the design, (vii) a surface temperature of any one or any combination of a topmost layer of the powder bed, the liquid melt zone, and the solidified melted surface in the processing area, and (viii) chemical composition characteristics of any one or any combination of the powder, the powder bed, the liquid melt zone, and the solidified melted surface.

11 . The device

Assignees

• Jones Eric
• Mullen Lewis
• Howmedica Osteonics Corp
• Univ Liverpool

Inventors

• Sutcliffe Christopher J
• Garrard Rebecca Helen
• Jones Eric
• Mullen Lewis
• Wong Hay

Classifications

• B23K15/0026 Primary

  Auxiliary equipment · CPC title

• B22F10/37

  of powder bed aspects, e.g. density · CPC title

• B22F12/90

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

• B22F12/44

  characterised by the configuration of the radiation means · CPC title

• B22F12/41

  characterised by the type, e.g. laser or electron beam · CPC title