Additive Manufacturing of Metals:
ICME Gaps: Material Property and Validation Data to Support Certification: Data Acquisition: Material Property and Validation Data to Support Certification
Sponsored by: TMS: Integrated Computational Materials Engineering Committee, TMS Additive Manufacturing Bridge Committee
Program Organizers: Joshua Fody, NASA Langley Research Center; Edward Glaessgen, NASA Langley Research Center; Christapher Lang, NASA Langley Research Center; Greta Lindwall, KTH Royal Institute of Technology; Michael Sansoucie, Nasa Marshall Space Flight Center; Mark Stoudt, National Institute of Standards and Technology
Monday 2:00 PM
October 18, 2021
Room: A114
Location: Greater Columbus Convention Center
Session Chair: Jonathan Raush, University of Louisiana at Lafayette; Michael Sansoucie, NASA
2:00 PM
High Temperature Material Properties Measurement Capabilities of the NASA MSFC Electrostatic Levitation (ESL) Laboratory: Michael Sansoucie1; 1NASA Marshall Space Flight Center
The NASA Marshall Space Flight Center (MSFC) electrostatic levitation (ESL) laboratory has a long history of providing materials research and thermophysical property data. The lab can measure thermophysical properties, such as density, surface tension, and viscosity of liquid materials, including elements, alloys, glasses, ceramics, and oxides. For improved measurement quality, the ESL lab also has an oxygen control system, which allows the oxygen partial pressure within the vacuum chamber to be measured and controlled, at elevated temperatures, over a wide range of partial pressures. The surface tension of metals is affected by even a small amount of adsorption of oxygen, and the presence of oxygen has been hypothesized as a likely cause for the large scatter seen in published surface tension data. This presentation will cover the MSFC ESL lab, its high temperature material properties measurement capabilities, and some information about measurements done on alloys relevant to additive manufacturing.
2:20 PM Invited
Laser Energy Coupling during Metal Additive Manufacturing: Brian Simonds1; 1NIST
The entire metal additive manufacturing process – from melting to solidification – is driven by the absorbed laser energy. Therefore, it is a quantity of great importance for multiscale, multiphysics model validation, but also one that is notoriously difficult to measure. At NIST-Boulder, we have implemented a light-scattering, energy balance approach based on integrating sphere radiometry. This has achieved nanosecond resolution; an expanded uncertainty of 1.3 %; and has been implemented on bare plate, metal powder, and during line scans. As this project aims to provide meaningful and complete data for model validation, we have combined absorption measurements with other quantitative real-time assessments of process dynamics. This is exemplified by a recent collaboration with Argonne National Laboratory where simultaneous absorption and high-speed synchrotron x-ray imaging measurements allowed specific melt pool dynamics to be correlated with their quantifiable effect on energy absorption. These efforts, and others, will be presented and discussed.
2:50 PM
An Analysis of the Dislocation Density of Inconel 718 Additive Manufacturing Powder: Colby Azersky1; Sangho Jeon2; Peggy Cebe3; 1NASA; 2Korea Research Institute of Standards and Science; 3Tufts University
Understanding and controlling the atomic dislocation density of metallic powders used for additive manufacturing processes is vital for the production of high fidelity additively manufactured parts. One-dimensional line defects are particularly important to the material properties of an additively manufactured part because these defects control yield stress and deformation behavior. Since these dislocations were introduced to the powder during the initial solidification, it is critical to investigate how undercooling and cooling rate affects the amount of internal dislocations. When these metallic powders are manufactured, their rapid cooling subjects them to significant undercooling during the solidification process. Multiple size ranges of Inconel 718 powder were evaluated using two different diffractometers to determine the relationship between cooling rate, undercooling and dislocation density. Line profile analysis of the X-ray diffraction patterns showed a significant increase in dislocation density at smaller particle sizes for both facilities.
3:10 PM Keynote
Providing a Rigorous Measurement Foundation for Modeling-Informed Qualification and Certification of Metal AM Components: Lyle Levine1; Brandon Lane1; Thien Phan1; Fan Zhang1; Mark Stoudt1; Brian Simonds1; David Deisenroth1; 1National Institute of Standards and Technology
Additive manufacturing (AM) is a transformative manufacturing technology that provides new capabilities across a wide range of material systems and applications. Metal AM enables customized production of three-dimensional parts with geometries that can be too costly, difficult, or in some cases, impossible to produce using traditional manufacturing processes. In many cases, however, difficulties persist regarding throughput, reproducibility, reliability, and properties of the printed parts. Critical gaps include a lack of alloy-specific and temperature-dependent material property data, model validation data for multi-scale and multi-physics AM simulations, and a rigorous calibration chain for in situ process monitoring and control. NIST is deeply involved in all these measurement issues and I will describe our current and planned work in these crucial areas and how this work fits into the landscape of metal AM qualification and certification.