Title: A laser powder bed fusion system for operando synchrotron x-ray imaging and correlative diagnostic experiments at the Stanford Synchrotron Radiation Lightsource

Abstract

Laser powder bed fusion (LPBF) is a highly dynamic multi-physics process used for the additive manufacturing (AM) of metal components. Improving process understanding and validating predictive computational models require high-fidelity diagnostics capable of capturing data in challenging environments. Synchrotron x-ray techniques play a vital role in the validation process as they are the only in situ diagnostic capable of imaging sub-surface melt pool dynamics and microstructure evolution during LPBF-AM. In this article, a laboratory scale system designed to mimic LPBF process conditions while operating at a synchrotron facility is described. The system is implemented with process accurate atmospheric conditions, including an air knife for active vapor plume removal. Significantly, the chamber also incorporates a diagnostic sensor suite that monitors emitted optical, acoustic, and electronic signals during laser processing with coincident x-ray imaging. The addition of the sensor suite enables validation of these industrially compatible single point sensors by detecting pore formation and spatter events and directly correlating the events with changes in the detected signal. Experiments in the Ti–6Al–4V alloy performed at the Stanford Synchrotron Radiation Lightsource using the system are detailed with sufficient sampling rates to probe melt pool dynamics. X-ray imaging captures melt pool dynamics at frame ratesmore » of 20 kHz with a 2 µm pixel resolution, and the coincident diagnostic sensor data are recorded at 470 kHz. Furthermore, this work shows that the current system enables the in situ detection of defects during the LPBF process and permits direct correlation of diagnostic signatures at the exact time of defect formation.« less

Authors:

Martin, Aiden A.  ^[1];

• Search DOE PAGES for author "Martin, Aiden A."
• Search DOE PAGES for ORCID "0000-0003-2362-5524"

Wang, Jenny ^[1]; DePond, Philip J. ^[1]; Strantza, Maria ^[1]; Forien, Jean-Baptiste  ^[1];

• Search DOE PAGES for author "Forien, Jean-Baptiste"
• Search DOE PAGES for ORCID "0000-0002-9229-2455"

Gorgannejad, Sanam ^[1]; Guss, Gabriel M. ^[1]; Thampy, Vivek ^[2]; Fong, Anthony Y.  ^[2];

• Search DOE PAGES for author "Fong, Anthony Y."
• Search DOE PAGES for ORCID "0000-0001-5296-5435"

Weker, Johanna Nelson  ^[2];

• Search DOE PAGES for author "Weker, Johanna Nelson"
• Search DOE PAGES for ORCID "0000-0001-6856-3203"

Stone, Kevin H.  ^[2];

• Search DOE PAGES for author "Stone, Kevin H."
• Search DOE PAGES for ORCID "0000-0003-1387-1510"

Tassone, Christopher J. ^[2]; Matthews, Manyalibo J. ^[1]; Calta, Nicholas P. ^[1]

---

+ Show Author Affiliations

1. Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
2. SLAC National Accelerator Lab., Menlo Park, CA (United States)

Publication Date:

Fri Apr 01 00:00:00 EDT 2022

Research Org.:

SLAC National Accelerator Laboratory (SLAC), Menlo Park, CA (United States); Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

Sponsoring Org.:

USDOE National Nuclear Security Administration (NNSA); USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE Office of Science (SC), Basic Energy Sciences (BES)

OSTI Identifier:

1882689

Alternate Identifier(s):

OSTI ID: 1860528; OSTI ID: 1880936

Report Number(s):

LLNL-JRNL-829176
Journal ID: ISSN 0034-6748; 21-ERD-008; TRN: US2307933

Grant/Contract Number:  

AC02-76SF00515; AC52-07NA27344; 21-ERD-008

Resource Type:

Accepted Manuscript

Journal Name:

Review of Scientific Instruments

Additional Journal Information:

Journal Volume: 93; Journal Issue: 4; Journal ID: ISSN 0034-6748

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

42 ENGINEERING; 47 OTHER INSTRUMENTATION; 36 MATERIALS SCIENCE; acoustics; photodiodes; x-ray imaging; synchrotron radiation; electronic signals; lasers