| Author(s) |
David Beaudry, Elaf A. Anber, Annie Barnett, Emily H. Mang, Michael Patullo, Syed Idrees A. Jalali, Demie Kepaptsoglou, Quentin Ramasse, Nathan Smith, Michael J. Waters, Xinran Zhou, Lauren Bowling, Jinxin Yu, Kevin J. Hemker, Elizabeth J. Opila, James M. Rondinelli, Christopher M. Wolverton, Jaime Marian, Michael L. Falk, Mitra L. Taheri |
| Abstract Scope |
The lattice-scale origins of deformation and damage behavior in BCC refractory alloys are examined with respect to the role of electronic structure and lattice dynamics through a combination of simulation, electron microscopy and spectroscopy, and high-temperature tensile testing. In particular, we present work connecting lattice instabilities inherent to the BCC structures to compositional dependence of preferential slip, twinning. High-temperature tensile testing of RMPEAs revealed the formation of nanoscale twins, which are linked to the local instabilities; high resolution spectroscopy confirms the presence of low-energy phonon features, confirming the connection of electronic structure-dictated deformation. Materials studied during high temperature testing were chosen from a suite of alloys that exhibited thermal stability during high temperature oxidation testing, owing to complex phase formation and local structure distribution. Finally, a discussion of radiation damage evolution processes in these alloys is also presented in the context of electronic structure, thus motivating a physics-based approach to alloy design in which electronic structure and lattice dynamic instabilities are treated as tunable variables governing deformation and damage mechanisms in refractory alloys and RMPEAs. |
