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.

Search Publications by: Thomas H. Gnaupel-Herold (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 98

Bottom-up Au Filling of Trenches in Curved Wafers

March 4, 2024
Author(s)
Daniel Josell, Thomas P. Moffat, Thomas Gnaupel-Herold, David Raciti, Martin Stauber, Yu Q, Liyang Chen, M Rawlik, Marco Stampanoni, Lucia Romano
A 〖Bi〗^(3+)-stimulated Au electrodeposition process in slightly alkaline 〖Na〗_3 Au(〖SO〗_3 )_2+〖Na〗_2 〖SO〗_3 electrolytes has been previously demonstrated for void-free extreme bottom-up filling of trenches with aspect ratios (height/width) exceeding 60 in

Bulk Elastic Constants And Their Role In Diffractive Stress Analysis

January 1, 2024
Author(s)
Thomas Gnaupel-Herold
The accuracy of stress determination depends to a large extent on the accuracy to which the diffraction elastic constants (DEC) can be obtained. DEC calculations require primarily single crystal elastic constants as input; however, large disparities

Elastic Behavior of Orientation-Correlated Grains in Multiphase Aggregates

December 1, 2023
Author(s)
Thomas Gnaupel-Herold
Diffraction elastic constants (DECs) describe the elastic response of a subset of orientation-correlated grains which share a common lattice vector. DECs reflect the elastic behaviour of the single-crystal constituents through their dependence on grain

Influence of Drawbeads in Deep Drawing of Plane-Strain Channel Sections

October 12, 2021
Author(s)
D E. Green, T B. Stoughton, Thomas H. Gnaupel-Herold, Mark Iadicola, Timothy J. Foecke
The Numisheet 2005 Benchmark 3 consisted of forming four different automotive sheet materials in a two-stage process. The first stage consisted of forming channel sections in an industrial-scale channel draw die in which material flow is controlled by

Two Stage Forming: Experimental and FE Analysis

October 12, 2021
Author(s)
M C. Oliveira, A J. Baptista, J L. Alves, L F. Menezes, D E. Green, Thomas H. Gnaupel-Herold, Mark Iadicola, Timothy J. Foecke, T B. Stoughton
One of the present challenges in sheet metal forming is to simulate sequential production stages, from the initial blank sheet to the final part ready for assembly. In this context, it is fundamental to evaluate the forming characteristics of the materials

Micromechanical Behaviorof Multilayered Ti/Nb Composites Processed by Accumulative Roll Bonding: An in-situ Synchrotron X-ray Diffraction Investigation

February 14, 2021
Author(s)
S. Jiang, R. L. Peng, Z. Hegedus, Thomas Gnaupel-Herold, J. J. Moverare, U. Lienert, F. Fang, X. Zhao, L. Zuo, N. Jia
Ti/Nb multilayered composites were fabricated by accumulative roll bonding (ARB). With increasing ARB cycles, shear bands become predominant in the continuously strengthened composites. The correlation between micromechanical behavior and mechanical

Elastic residual strain and stress measurements and corresponding part deflections of 3D AM builds of IN625 AM-Bench artifacts using neutron diffraction, synchrotron X-ray diffraction, and contour method

July 29, 2019
Author(s)
Thien Q. Phan, Maria Strantza, Michael R. Hill, Thomas H. Gnaupel-Herold, Jarred C. Heigel, Christopher D'Elia, DeWald Adrian, Bjorn Clausen, Darren C. Pagan, J. Y. Peter Ko, Donald W. Brown, Lyle E. Levine
One of the primary barriers for acceptance of additive manufacturing (AM) has been the uncertainty in the performance of AM parts due to residual stresses/strains. The rapid heating and cooling rates, along with the thermal history of the laser melting

Fracture Mechanics Approach to Splitting in Low Spring Index Cold Coiling Process

June 1, 2019
Author(s)
Y. Prawoto, S. Manville, T. Sakai, L. Lee, M. Tanaka, Thomas H. Gnaupel-Herold
This paper is an attempt to understand the coil splitting phenomena by means of fracture mechanics. The methods used combines the residual stress measurement with neutron and finite element analysis. The support of the metallurgical evaluation is used as

Residual Stress in Additive Manufactured Nickel Alloy 625 Parts

June 29, 2018
Author(s)
Lindsey B. Bass, Justin L Milner, Thomas H. Gnaupel-Herold, Shawn P. Moylan
One of the key barriers to widespread adoption of additive manufacturing (AM) for metal parts is the build-up of residual stresses. In the laser-based powder bed fusion process, a laser selectively fuses metal powder layer by layer, generating significant