Abstract
Studies utilizing neutron diffraction have been a consideration since the 1940s and are relatively commonplace today. Join us for a discussion on the background about the history of neutron diffraction, including the 50 plus year history of neutron research at Oak Ridge National Laboratory. Neutron diffraction has proven a valuable tool for materials characterization, specifically for the technique’s merits in residual stress mapping. Neutron diffraction allows for non-destructive spatial characterization of residual stresses in engineering materials with deep penetration, as opposed to x-ray diffraction which can only characterize the surface stress state. However, neutrons are not a common laboratory tool, and require large user facilities to be operated and maintained. This presentation will also include a basic overview of neutron diffraction in engineering materials and their use in mapping residual stresses in welding applications. For those interested, information on how users can access the neutron facilities at ORNL will be provided.
About the speaker
Jeff Bunn is the lead instrument scientist at the residual stress diffractometer (HIDRA) located at the High Flux Isotope Reactor (HFIR) at Oak Ridge National Laboratory. He obtained his B.S. in Engineering from The University of Tennessee at Martin in 2007 and his Ph.D. in Civil Engineering from the University of Tennessee at Knoxville in 2014. He first came to ORNL in 2006 as an undergraduate intern working at the High Temperature Materials Laboratory utilizing x-ray and neutron diffraction for strain determination in engineering materials. Following his Ph.D., he returned to ORNL as a postdoctoral research associate in the Chemical and Engineering Materials Division and in 2014 and was hired permanently as an instrument scientist in 2017. His past and current research interests are within applied materials research of engineering materials. Some of the broad research topics he has explored are concerning material responses to complex loadings (biaxial torsion, combined tension and torsion, or proportional loadings) measured by neutron and x-ray diffraction, material responses to joining, such as welding. He also has worked on new data analysis tools for reduction and visualization of neutron and X-ray data. He has a continued interest in neutron imaging for the purpose of strain, texture and phase in engineering materials.
DATE: Tuesday, December 8, 2020
7:00 pm Networking7:30 pm Presentation8:15 pm Q&AThe virtual meeting will be hosted by Ring Central Meetings (ASM's Zoom client). There is no charge for the meeting. Optional RSVP to chair@asm-dc.org to ensure you have a spot!