Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Measurement of mass loss, absorbed energy, and time-resolved reflected power for laser powder bed fusion

Published

Author(s)

David C. Deisenroth, Sergey Mekhontsev, Brandon M. Lane

Abstract

Laser powder bed fusion processes are driven by scanned, focused laser beams. Along with selectively melting the metal powder, laser energy may be converted and transferred through physical mechanisms such as reflection from the metal surface, heat absorption into the substrate, vaporization, spatter, ejection of heated particles, and superheating of the metal vapor/condensate plume generated by laser-metal interaction. Reliable data on energy transfer can provides inputs for the process modeling, as well as help validate computational models results. Additionally, some related process signatures can serve better process monitoring and optimization. Previous studies have shown that the proportion of the transfer mechanisms depend on laser power, spot size, and scan speed. In the current investigation, the energy conservation principle was used to validate our measurement of reflected energy, absorbed energy, and energy transfer by vaporization on bare plates of Nickel Alloy 625 (IN625). Heat absorbed into the substrate was measured by calorimetry. The mass transfer from the sample was measured with a precision balance and used to establish an upper bound of energy transfer by mass transfer. In addition to measurement of total reflected energy, the reflected laser power was time-resolved at 50 kHz in an integrating hemisphere, which provided insight into the process dynamics in conduction, transition, and keyhole modes.
Proceedings Title
Proc. SPIE Photonics West
Conference Dates
February 1-6, 2020
Conference Location
San Francisco, CA
Conference Title
SPIE Photonics West

Keywords

Laser powder bed fusion, laser coupling, energy transfer in laser melting

Citation

Deisenroth, D. , Mekhontsev, S. and Lane, B. (2020), Measurement of mass loss, absorbed energy, and time-resolved reflected power for laser powder bed fusion, Proc. SPIE Photonics West, San Francisco, CA, [online], https://doi.org/10.1117/12.2547491 (Accessed November 24, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created March 2, 2020, Updated May 6, 2020