FLaMI

Fundamentals of Laser-Matter Interaction Testbed

The FLaMI system is a very accurate, well characterized, and highly configurable laser processing testbed that was designed to study the fundamentals of laser-matter interaction (FLaMI) in-situ, with focused application towards laser-based additive manufacturing metals (AM-LB/M). 

Additive manufacturing by PBF-LB/M is increasingly embraced across a variety of industries and applications due various advantages over traditional manufacturing. Such advantages include manufacturing of complex part geometries, short lead times from design to fabrication, and utilization of unique materials. However, broader adoption of this manufacturing technology requires that computational models and in-situ monitoring of such processes be experimentally validated under highly controlled conditions with advanced metrology. Validation of models and in-situ monitoring systems are especially important for critical AM part applications that require qualification and certification. Such controlled conditions and advanced metrology cannot be readily implemented in commercial AM-LB/M machines due to a variety of constraints and unknowns about machine performance. Therefore, this very accurate, well characterized, and highly configurable laboratory testbed has been developed at NIST. 

Overview of FLaMI Research

FLaMI Testbed Research Goals

Groundbreaking metrology, data, and insights that support advancement of metal L-PBF and L-DED:

1. Exceptional characterization of predominant process parameters, with particular focus on laser beam power density distributions
2. Conception and advancement of metrology for critical model inputs and innovative process monitoring methods, with particular focus on metrology for reflected laser power and directional distributions <DRLC video coming soon>
3. Unparalleled accuracy and uncertainty quantification of melt pool thermal distributions
4. Highly-novel data of the byproduct plume for improved process monitoring, gas flow optimization, and scan strategy development < backlit ejecta video coming soon>

Example Video Data

Hemispherical distribution of reflected laser power imaged with an equiangular fisheye lens. The laser is scanned from left to right and imaged at 60,000 frames per second with angular resolution of 0.65 degrees per pixel. These high-speed directionally resolved laser power distributions provide a new high-fidelity model validation approach, as well as support of a novel and highly-promising process monitoring approach.

< DRLC video coming soon>

Side view of byproduct ejecta with backlighting. The laser is scanned from left to right and imaged at 67,500 frames per second with resolution of 14.5 μm/pixel. The horizontal viewing angle and orthogonal perspectives of two high-speed imagers allow for 3-dimensional measurements of the plume structure, as well as measurement of ejecta sizes, quantities, and velocities, which strongly relate to material feedstock redistribution and the resulting quality of built parts.

Side view of byproduct ejecta with backlighting

Collaboration

NIST is open to collaborations on projects that can make use of the special capabilities of the FlaMI.  Unofficial collaborations are preferred, with topics that fall under the research goals of the FLaMI and the Measurement Science for Additive Manufacturing Program, and any results can be made public and co-published by NIST.  Official collaborations can be conducted through a Cooperative Research and Development Agreement (CRADA).

Want to work with the FLaMI? Various opportunities exist for guest researchers, post-doctoral researcher associates, or for Ph.D. students through the NIST Pathways internship program.  

NIST Staff

David Deisenroth

Sergey Mekhontsev

Jordan Weaver

Relevant Publications

1. Deisenroth D, Weaver J, Mekhontsev S, Grantham S, Moylan S (2025) Laser Beam Metrology for AM-Bench 2022: Approaches, Results, and Lessons Learned. (National Institute of Standards and Technology, Gaithersburg, MD), NIST Advanced Manufacturing Series (AMS) NIST AMS 100-67. https://doi.org/10.6028/NIST.AMS.100-67
2. Deisenroth D, Mekhontsev S, Grantham S (2025) Design and Calibration of the Fundamentals of Laser-Matter Interaction (FLaMI) Powder Bed Fusion Testbed at the National Institute of Standards and Technology. NIST Advanced Manufacturing Series (AMS) 100–66. https://doi.org/10.6028/NIST.AMS.100-66
3. Deisenroth D, Mekhontsev S, Weaver J, Webster S (2024) Laser power density distribution metrology to support emerging trends in metal Additive Manufacturing. 13th CIRP Conference on Photonic Technologies [LANE 2024], 15-19 September 2024, Fürth, Germany 124:741–745. https://doi.org/10.1016/j.procir.2024.08.215
4. Huang W, Deisenroth D, Mekhontsev S, Tan W (2023) Correlation between keyhole geometry and reflected laser light distribution in laser-based manufacturing. Manufacturing Letters 38:56–59. https://doi.org/10.1016/j.mfglet.2023.09.002
5. Deisenroth D, Mekhontsev S, Lane B, Hanssen L, Zhirnov I, Khromchenko V, Grantham S, Cardenas-Garcia D, Donmez A (2021) Measurement Uncertainty of Surface Temperature Distributions for Laser Powder Bed Fusion Processes. Journal of Research of NIST 126. https://doi.org/10.6028/jres.126.013
6. Deisenroth DC, Neira J, Weaver J, Yeung H (2020) Effects of Shield Gas Flow on Meltpool Variability and Signature in Scanned Laser Melting. MSEC2020 (Volume 1: Additive Manufacturing; Advanced Materials Manufacturing; Biomanufacturing; Life Cycle Engineering; Manufacturing Equipment and Automation). https://doi.org/10.1115/MSEC2020-8410
7. Deisenroth DC, Mekhontsev S, Lane S (2020) Measurement of mass loss, absorbed energy, and time-resolved reflected power for laser powder bed fusion., Proc. SPIE 11271, Laser 3D Manufacturing VII, p 112710L. https://doi.org/10.1117/12.2547491

Relevant Web Pages

Measurement Science for Additive Manufacturing Program (MSAM)

The objective of the MSAM program is to develop and deploy measurement science that will enable rapid design-to-product transformation through advances in: material characterization; in-process process sensing, monitoring, and model-based optimal control; performance qualification of materials, processes and parts; and end-to-end digital implementation of metal Additive Manufacturing processes and systems. Please check-out the other great research activities in the program.

Additive Manufacturing Benchmark Series (AM-Bench)

AM-Bench is a continuing series of controlled benchmark tests, in conjunction with a conference series, to allow modelers to test their simulations against AM test data, and to encourage AM practitioners to develop novel mitigation strategies for challenging build scenarios. The LPBF Thermography system is used to provide data for the AM-Bench and many of the experiments are used to help develop the benchmark tests.

LPBF Thermography

This website provides an overview of the thermography performed on the commercial laser powder bed fusion (LPBF) thermography system at NIST.  This website provides measurement data that can be used to validate models of LPBF.