@article {1691,
	title = {Multiplicity of dislocation pathways in a refractory multiprincipal element alloy},
	journal = {Science},
	volume = {370},
	year = {2020},
	pages = {95{\textendash}101},
	abstract = {<p>
	Refractory multiprincipal element alloys (MPEAs) are promising materials to meet the demands of aggressive structural applications, yet require fundamentally different avenues for accommodating plastic deformation in the body-centered cubic (bcc) variants of these alloys. We show a desirable combination of homogeneous plastic deformability and strength in the bcc MPEA MoNbTi, enabled by the rugged atomic environment through which dislocations must navigate. Our observations of dislocation motion and atomistic calculations unveil the unexpected dominance of nonscrew character dislocations and numerous slip planes for dislocation glide. This behavior lends credence to theories that explain the exceptional high temperature strength of similar alloys. Our results advance a defect-aware perspective to alloy design strategies for materials capable of performance across the temperature spectrum.
</p>
},
	issn = {10959203},
	doi = {10.1126/science.aba3722},
	author = {Wang, Fulin and Balbus, Glenn H. and Xu, Shuozhi and Su, Yanqing and Shin, Jungho and Rottmann, Paul F. and Knipling, Keith E. and Stinville, Jean Charles and Mills, Leah H. and Senkov, Oleg N. and Beyerlein, Irene J. and Pollock, Tresa M. and Gianola, Daniel S.}
}
@article {1486,
	title = {Femtosecond laser rejuvenation of nanocrystalline metals},
	journal = {Acta Materialia},
	volume = {156},
	year = {2018},
	pages = {183{\textendash}195},
	abstract = {<p>
	Nanocrystalline metals are distinct from traditional engineering materials due to their high concentration of grain boundaries and corresponding structural disorder at grain boundaries. The effect of local disorder in nanocrystalline materials manifests in ways reminiscent of fully amorphous materials, such as mesoscale shear localization and pressure-dependent yielding, owing to the high concentration of grain boundaries and their predominance in governing plasticity. Relaxation processes in nanocrystalline materials that facilitate reconfigurations of grain boundaries and lower their energy, such as low temperature annealing, have been shown to enhance mechanical strength. However, processes that raise the energy of a nanocrystalline metal have not been observed, limiting the tunability of properties and the prospect for suppressing shear localization. Here, we use femtosecond laser processing as a unique non-equilibrium process that can generate complex stress states due to ultrafast electronic excitation and subsequent relaxation events. Experiments on nanocrystalline Al-O and Cu-Zr alloys indicate that sub-ablation femtosecond laser pulses cause up to an 87\% reduction in hardness with no change in grain size, which can be ascribed to grain boundary-mediated processes. Parallels between our results and rejuvenation processes in glassy systems will be discussed in the context of controlling metastable structural configurations through novel processing routes.
</p>
},
	keywords = {Femtosecond lasers, Grain boundaries, Nanocrystalline, Rejuvenation},
	issn = {13596454},
	doi = {10.1016/j.actamat.2018.06.027},
	url = {https://doi.org/10.1016/j.actamat.2018.06.027},
	author = {Balbus, Glenn H. and Echlin, Mclean P. and Grigorian, Charlette M. and Rupert, Timothy J. and Pollock, Tresa M. and Gianola, Daniel S.}
}
