Resumen:
Advantages of neutron diffraction for metallurgical studies are highlighted with research examples performed on the High Pressure – Preferred Orientation (HIPPO) diffractometer at the Los Alamos Neutron Science Center (LANSCE). We give a brief introduction of neutron diffraction and an overview of LANSCE. Neutrons offer unique advantages in particular for bulk microstructural characterization such as texture and phase composition. Therefore, the concept of neutron texture measurements will be introduced and its advantages discussed. As an example, we derive an explanation for observed texture memory effects during the a®g®a transformation cycle in a 0.1%C-1%Mn hot-rolled steel sheet from the Kurdjumov-Sachs relationship. As an example for crystallographic studies of intermetallics, we describe how the previously inconclusive crystallographic structure of the Fe-Al ε phase, stable between 1095°C and 1231°C, was determined by in situ neutron diffraction to have the formula Fe5Al8 with a body-centered cubic structure of the Hume–Rothery Cu5Zn8 type at 1120°C. Microstructure evolution in a Zr-2.5Nb alloy during two heating and cooling cycles to 900°C will be also discussed.
We will also discuss efforts by our colleagues at the Julich research center, led by Thomas Gutberlet, on building a compact neutron source based on the Julich High Brilliance Source concept at the Zamudio facility at ESS Bilbao. This facility is planned to be operational in 2026 and may offer collaboration opportunities.
Bio:
Sven Vogelreceived a Ph.D. (Dr. rer. nat.) in Physics in 2000 from Christian-Albrechts University, Kiel, Germany, and holds diplomas (equivalent to U.S. master degree) in physics and mineralogy from the same university. In 2001 he came to Los Alamos National Laboratory as a postdoc in the Materials Science and Technology Division and became staff in 2002 at the Los Alamos Neutron Science Center (LANSCE). His research interests include deformation mechanisms and phase transformations in metals, alloys, and rocks; in-situ neutron and synchrotron diffraction loading measurements; texture measurements; phase transformation textures; Bragg-edge and resonance absorption neutron transmission and imaging; radiography & tomography. He has operated the neutron diffractometer HIPPO at LANSCE since 2002, with over 400 user proposals carried out. He received the Award of Excellence for a significant contribution to the stockpile stewardship in 2005 and 2009 and the LANSCE User Facility Director’s Award 2009. He is also Faculty Adjunct at New Mexico Institute of Mining and Technology (2011-present). Sven has authored and co-authored over 400 publications with over 10,000 citations per Google Scholar and contributed to chapters for several textbooks.
