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Search Publications by: Mark R. Stoudt (Fed)

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Displaying 26 - 50 of 136

Simulation of TTT curves for additively manufactured Inconel 625

January 1, 2019
Author(s)
Carelyn E. Campbell, Greta Lindwall, Eric Lass, Fan Zhang, Mark R. Stoudt, Andrew J. Allen, Lyle E. Levine
The ability to use common computational thermodynamic and kinetic tools to study the microstructure evolution in Inconel 625 (IN625) manufactured using the additive manufacturing (AM) technique of laser powder-bed fusion is evaluated. Solidification

The Effects of Laser Powder Bed Fusion Process Parameters on Material Hardness and Density for Nickel Alloy 625

August 21, 2018
Author(s)
Christopher U. Brown, Gregor Jacob, Antonio M. Possolo, Carlos R. Beauchamp, Max A. Peltz, Mark R. Stoudt, M A. Donmez
The goal of this study was to investigate the relationship between mechanical and material properties (including density) of manufactured nickel super alloy (IN625) using a laser powder bed fusion process and three process parameters: laser power, hatch

Systems Design Approach to Low-Cost Coinage Materials

June 20, 2018
Author(s)
Eric Lass, Mark R. Stoudt, Carelyn E. Campbell
A system design approach using an Integrated Computational Materials Engineering (ICME) was used to design three new low-cost seamless replacement coinage alloys to reduce the raw material of the current US coinage alloys. Maintaining compatibility with

Effect of Heat Treatment on the Microstructural Evolution of a Nickel-Based Superalloy Additive-Manufactured by Powder Bed Fusion Laser Sintering

June 15, 2018
Author(s)
Fan Zhang, Lyle E. Levine, Andrew J. Allen, Mark R. Stoudt, Greta Lindwall, Eric Lass, Maureen E. Williams, Yaakov S. Idell, Carelyn E. Campbell
Elemental segregation is a ubiquitous phenomenon in additive-manufactured (AM) parts due to solute rejection and redistribution during the rapid solidification process. Using electron microscopy, in situ synchrotron X-ray scattering and diffraction, and

The Influence of Annealing Temperature and Time on the Formation of delta-Phase in Additively-Manufactured Inconel 625

May 10, 2018
Author(s)
Mark R. Stoudt, Eric Lass, Daniel S. Ng, Maureen E. Williams, Fan Zhang, Carelyn E. Campbell, Greta Lindwall, Lyle E. Levine
This research evaluated the kinetics of delta-phase growth in laser powder bed additively- manufactured (AM) Inconel 625 during post-build stress-relief heat treatments. The temperatures ranged between 650 °C to 1050 °C, and the times from 0.25 h to 168 h

Formation of Nb-rich droplets in laser deposited Ni-matrix microstructures

March 15, 2018
Author(s)
Supriyo Ghosh, Mark R. Stoudt, Lyle E. Levine, Jonathan E. Guyer
Ni-rich $\gamma$ cells/dendrites and Nb-rich eutectic droplets that form during laser power bed fusion (LPBF) solidification of Ni-Nb alloys are studied in the present work using numerical simulations. Finite element simulations estimate the local cooling

Single Track Melt Pool Measurements and Microstructures in Inconel 625

February 20, 2018
Author(s)
Supriyo Ghosh, Li Ma, Lyle E. Levine, Richard E. Ricker, Mark R. Stoudt, Jarred C. Heigel, Jonathan E. Guyer
We use single track laser melting experiments and simulations on Inconel 625 to estimate the dimensions and microstructures of the resulting melt pools. Our work is based on a design-of- experiments approach which uses multiple laser power and scan speed

Formation of the Ni3Nb delta-phase in stress-relieved Inconel 625 produced via powder-bed laser fusion additive manufacturing

August 23, 2017
Author(s)
Eric Lass, Mark R. Stoudt, Maureen E. Williams, Michael B. Katz, Thien Q. Phan, Lyle E. Levine, Thomas H. Gnaeupel-Herold
The microstructural evolution of laser powder-bed additively manufactured Inconel 625 during a post-build stress-relief anneal of 1 h at 870 °C is investigated. It is found that this industry-recommended heat treatment promotes the formation of a