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Search Publications by: Nik Hrabe (Fed)

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Displaying 76 - 92 of 92

Fatigue measurement of pipeline steels for application of gaseous hydrogen transport

February 5, 2018
Author(s)
Andrew J. Slifka, Elizabeth S. Drexler, Robert L. Amaro, Louis E. Hayden, Damian S. Lauria, Nikolas W. Hrabe, Douglas G. Stalheim
A comprehensive testing program to determine the fatigue crack growth rate of pipeline steels in pressurized hydrogen gas was completed; the project was sponsored by the Department of Transportation, and was conducted in close collaboration with the ASME

Instrumented impact testing of miniaturized Charpy specimens of AM Ti 6Al 4V

November 16, 2017
Author(s)
Enrico Lucon, Nikolas W. Hrabe
An investigation on the impact toughness properties of wrought and additively-manufactured (AM) Ti 6Al 4V was conducted at NIST Boulder, by means of instrumented impact tests on miniaturized Charpy specimens. Full transition curves for absorbed energy and

Metal Additive Manufacturing Standardization in Support of Qualification and Certification

February 28, 2017
Author(s)
Mohsen Seifi, Michael Gorelik, Jess Waller, Nik Hrabe, Nima Shamsaei, Steve Daniewicz, John J. Lewandowski
As the metal Additive Manufacturing (AM) industry moves towards industrial production, the need for qualification standards covering all aspects of the technology becomes ever more prevalent. While some standards and specifications for documenting the

Effects of Processing on Microstructure and Mechanical Properties of Ti-6Al-4V Fabricated using Electron Beam Melting (EBM), Part 2: Energy Input, Orientation, and Location

June 20, 2013
Author(s)
Nikolas W. Hrabe, Timothy P. Quinn, Ryan Kircher
Selective electron beam melting (EBM) is a layer-by-layer additive manufacturing technique that shows great promise for fabrication of medical devices and aerospace components. Before its potential can be fully realized, however, a deeper understanding of

Effects of Processing on Microstructure and Mechanical Properties of Ti-6Al-4V Fabricated using Electron Beam Melting (EBM), Part 1: Distance from Build Plate and Part Size

June 20, 2013
Author(s)
Nikolas W. Hrabe, Timothy P. Quinn, Ryan Kircher
Selective electron beam melting (EBM) is a layer-by-layer additive manufacturing technique that shows great promise for fabrication of medical devices and aerospace components. Before its potential can be fully realized, however, a deeper understanding of