Building parts by welding millions of little bits of metal together: what could possibly go wrong?
Lyle E Levine
National Institute of Standards and Technology, Material Measurement Laboratory, Gaithersburg, MD 20899-8553 USA, Lyle.Levine@nist.gov
Abstract: Additive manufacturing (AM) of metals could revolutionize the design and production of complex, high-value metal parts. However, the extreme processing conditions of welding millions of microscopic bits of metal together create deleterious microstructures with high stresses, extreme compositional gradients, non-equilibrium phases, and a host of potentially disastrous build flaws. Substantial post processing is typically required to achieve useable mechanical properties, but position-dependent variations within the part and life-cycle issues such as fatigue and corrosion greatly complicate part qualification. To overcome these challenges, NIST and partners have developed world-leading in situ control and characterization of the build process, world-leading in situ and ex situ characterization and modeling of the as-built and post-processed microstructure and stresses, and rigorous characterization and modeling of the in-service material behavior. Ultimately, completely new alloys that are tailored for additive manufacturing must be developed. I will describe our work in these areas on AM steels and Ni-based super alloys. Finally, I will describe our establishment of the Additive Manufacturing Benchmark Test Series (AM-Bench), a continuing series of highly controlled benchmark measurements for additive manufacturing that allows modelers around the world to test their simulations against rigorous, highly controlled AM benchmark test data.
Short Bio: Dr. Lyle Levine is a physicist in the Materials Measurement Laboratory of the National Institute of Standards and Technology (NIST) in the USA, where he leads most of NIST’s materials research in additive manufacturing (AM) of metals. With a dual emphasis on world-leading, quantitative measurements and microstructure evolution modeling, this Additive Manufacturing of Metals Project provides experimental input and validation testing for both high-fidelity AM models and reduced order models for AM engineering design. Dr. Levine also founded and leads AM-Bench, an international organization that provides AM benchmark measurements for the AM community. With active participation from more than 80 organizations around the world AM-Bench is the world’s leading provider for AM benchmark data. Dr. Levine also leads the experimental validation effort for ExaAM, a DOE-funded collaboration between Oak Ridge National Laboratory, Lawrence Livermore National Laboratory, Los Alamos National Laboratory, and NIST that is developing AM simulation codes for the world’s first exa-scale computers. In addition to his work on AM, Dr. Levine founded the continuing Dislocations Conference Series and is highly active in synchrotron X-ray science, where he co-develops and uses world-leading microbeam diffraction and small-angle scattering methods for studying material microstructures. Dr. Levine received his B.S. in physics from Caltech and his Ph.D. in physics from Washington University in St. Louis. He is an adjunct professor of Mechanical Engineering at both Northwestern University and the University of Southern California, where he advises graduate students. Dr. Levine is a recipient of NIST’s highest honor for innovations in measurement science, the Allen V. Astin Measurement Science Award; the U.S. Department of Commerce Silver and Bronze Medals; the TMS Nagy El-Kaddah Award, and the ASM Henry Marion Howe Medal.
Please join us at 3:30pm prior to the seminar for Tea Time in Wilsdorf Room 109A.