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Search Publications by: Maureen E. Williams (Fed)

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Displaying 1 - 25 of 53

Phase Composition and Phase Transformation of Additively Manufactured Nickel Alloy 718 AM Bench Artifacts

February 5, 2024
Fan Zhang, Aaron Johnston-Peck, Lyle E. Levine, Michael Katz, Kil-Won Moon, Maureen E. Williams, Sandra W. Young, Andrew J. Allen, Olaf Borkiewicz, Jan Ilavsky
Additive Manufacturing (AM) technologies offer unprecedented design flexibility but are limited by a lack of understanding of the material microstructure formed under their extreme and transient processing conditions and its subsequent transformation

Developing an Appropriate Heat Treatment Protocol for Additively Manufactured Alloy 718 for Oil and Gas Applications

March 23, 2023
Mark R. Stoudt, James Zuback, Carelyn E. Campbell, Maureen E. Williams, Kil-Won Moon, Carlos R. Beauchamp, Mark Yunovich
The combination of strength, corrosion resistance, and excellent weldability makes Alloy 718 an attractive alloy for additive manufacturing (AM) applications, but the AM build process generates considerable residual stresses, and large compositional and

Development of a Diffusion Mobility Database for Co-based Superalloys

November 27, 2022
Greta Lindwall, Kil-Won Moon, Carelyn E. Campbell, Maureen E. Williams, Whitney Tso
To facilitate the development of high-temperature Co-based - superalloys, a Co-Ni based diffusion mobility database is developed for the eight component FCC (Face Centered Cubic) system of Co-Al-W-Ni-Cr-Ti-Ta-Re. A CALPHAD approach is used to represent

Robust Bottom-Up Gold Filling of Deep Trenches and Gratings

March 25, 2022
Daniel Josell, William Alexander Osborn, Maureen E. Williams
This work extends application of an extreme variant of superconformal Au electrodeposition to deeper device architectures while exploring factors that constrain its function and thereby the robustness of void-free processing. The unconventional bottom-up

How Austenitic is a Martensitic Steel Produced by Laser Powder Bed Fusion? A Cautionary Tale

December 2, 2021
Fan Zhang, Mark R. Stoudt, Souzan Hammadi, Carelyn E. Campbell, Eric A. Lass, Maureen E. Williams
Accurate phase fraction analysis is an essential element of microstructural characterization of alloys and often serves as a basis to quantify effects such as heat treatment or mechanical deformation. Additive manufacturing (AM) of metals, due to the

NEMI Tin Whisker Test Method Standards

October 12, 2021
I Boguslavsky, P Bush, E Kam-Lum, M Kwoka, J McCullen, K Spalding, K Vo, Maureen E. Williams
The need to better understand whisker growth has dramatically increased as component suppliers convert from tin-lead (SnPb) finishes to Pb-free finishes of Sn and low -alloy-content Sn-based finishes. Whiskers are spontaneous growth of metal filaments

Tin Whisker Test Method Development

October 12, 2021
Valeska Schroeder, P Bush, Nick Vo, Maureen E. Williams
In response to legislation banning Pb from electronics, any component suppliers plan to implement tin-based lead-free surfaces finishes to replace current Sn-Pb finishes. The industry needed a test for assessing the susceptibilty of tin-based finishes to

Development of Computational Framework for Titanium Alloy Phase Transformation Prediction in Laser Powder-bed Direct Energy Additive Manufacturing

October 16, 2020
Zhi Liang, Ivan Zhirnov, Fan Zhang, Kevontrez K. Jones, David C. Deisenroth, Maureen E. Williams, Ursula R. Kattner, Kil-Won Moon, Wing-Kam Liu, Brandon M. Lane, Carelyn E. Campbell
In conjunction with bare metal single laser track validation experiments, a computational framework is proposed to accelerate the design and development of new additive manufacturing (AM) specific alloys. Specifically, Additive Manufacturing-Computational

Location-specific Microstructure Characterization Within IN625 Additive Manufacturing Benchmark Test Artifacts

March 3, 2020
Mark R. Stoudt, Maureen E. Williams, Lyle E. Levine, Adam Abel Creuziger, Sandra A. Young, Jarred C. Heigel, Brandon Lane, Thien Q. Phan
Additive manufacturing (AM) of metals creates segregated microstructures with significant differences from those of traditional wrought alloys. Understanding how the local build conditions generate specific microstructures is essential for developing post

Exploring the Limits of Bottom-Up Gold Filling to Fabricate Diffraction Gratings

November 27, 2019
Daniel Josell, Stephen J. Ambrozik, Maureen E. Williams, A E. Hollowell, Christian Arrington, Shinichiro Muramoto, Thomas P. Moffat
Gold deposition on rotating disk electrodes, Bi3+ adsorption on planar Au films and superconformal Au filling of trenches up to 45 m deep are examined in Bi+3-containing Na3Au(SO3)2 electrolytes with pH between 9.5 and 11.5. Higher pH is found to increase

Phase Fraction and Evolution of Additively Manufactured 15-5 Stainless Steel and Inconel 625 AM- Benchmark Artifacts

August 5, 2019
Fan Zhang, Lyle E. Levine, Andrew J. Allen, Sandra A. Young, Maureen E. Williams, Mark R. Stoudt, Kil-Won Moon, Jarred C. Heigel, Jan Ilavsky
A proper understanding of the structure and microstructure of additive manufactured (AM) alloys is essential not only to the prediction and assessment of their material properties, but also to the validation and verification of computer models essential to

Accelerated Bottom-up Gold Filling of Trenches

July 12, 2019
Daniel Josell, Maureen E. Williams, Stephen J. Ambrozik, Chen Zhang, Thomas P. Moffat
This work extends previously detailed void-free, bottom-up feature filling in a near-neutral Na3Au(SO3)2 + Na2SO3 electrolyte containing micromolar concentrations of Bi. Bottom-up electrodeposition in 17 m and 45 m tall trenches is demonstrated using

Solidification of Ni-Re Peritectic Alloys

February 4, 2019
William J. Boettinger, Dale E. Newbury, Nicholas W. Ritchie, Maureen E. Williams, Ursula R. Kattner, Eric Lass, Kil-Won Moon, Michael B. Katz
Differential thermal analysis (DTA) and microstructural and microprobe measurements of DTA and as-cast Ni-Re alloys with compositions between 0.20 and 0.44 mass fraction Re provide information to resolve differences in previously published Ni-Re phase

Diffusion in the Ti-Al-V system

August 23, 2018
Greta Lindwall, Kil-Won Moon, Zhangqi Chen, Michael J. Mengason, Maureen E. Williams, Justin Gorham, Ji-Cheng Zhao, Carelyn E. Campbell
Diffusion in the Ti-Al-V system is studied and a CΑLPHAD diffusion mobility description is developed. Diffusion couple experiments are used to obtain information of Al and V diffusion in the α phase. This includes diffusion paths at the temperatures 923 K

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

June 15, 2018
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
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

Application of Finite Element, Phase-field, and CALPHAD-based Methods to Additive Manufacturing of Ni-based Superalloys

September 21, 2017
Trevor Keller, Greta Lindwall, Supriyo Ghosh, Li Ma, Brandon M. Lane, Fan Zhang, Ursula R. Kattner, Eric Lass, Yaakov S. Idell, Maureen E. Williams, Andrew J. Allen, Jonathan E. Guyer, Lyle E. Levine
Numerical simulations are used in this work to investigate aspects of microstructure and microsegregation during rapid solidification of a Ni-based superalloy in a laser powder bed fusion additive manufacturing process. Thermal modeling by finite element

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

August 23, 2017
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

Interdiffusion in the Ni-Re System: Evaluation of Uncertainties

June 23, 2017
William J. Boettinger, Maureen E. Williams, Kil-Won Moon
Diffusion couple experiments between Ni and Re at 1200°C and 1350°C were performed. These experiments established the limits of the two-phase FCC + HCP region. No intermediate phase was observed at these temperatures. Composition dependent interdiffusion

Homogenization Kinetics of a Nickel-based Superalloy Produced by Powder Bed Fusion Laser Sintering

January 26, 2017
Fan Zhang, Lyle E. Levine, Andrew J. Allen, Eric Lass, Sudha Cheruvathur, Mark R. Stoudt, Maureen E. Williams, Yaakov S. Idell, Carelyn E. Campbell
Additively manufactured (AM) metal components often exhibit fine dendritic microstructures and elemental segregation due to the initial rapid solidification and subsequent melting and cooling during the build process, which without homogenization would

Diffusion in FCC Co-Al-W Alloys at 900 degree C and 1000 degree C

August 17, 2016
Kil-Won Moon, Carelyn E. Campbell, Maureen E. Williams, William J. Boettinger
Diffusion couple experiments between various Co-rich face centered cubic alloys in the Co-W-Al ternary system have been conducted at 900 degree C and 1000 degree C. Diffusion coefficients have been extracted for the Co-W binary and for ternary alloys at