title: Plasticity mechanisms in HfN at elevated and room temperature.
abstract: HfN specimens deformed via four-point bend tests at room temperature and at 2300 °C (~0.7 Tm) showed increased plasticity response with temperature. Dynamic diffraction via transmission electron microscopy (TEM) revealed ⟨110⟩{111} as the primary slip system in both temperature regimes and ⟨110⟩{110} to be a secondary slip system activated at elevated temperature. Dislocation line lengths changed from a primarily linear to a curved morphology with increasing temperature suggestive of increased dislocation mobility being responsible for the brittle to ductile temperature transition. First principle generalized stacking fault energy calculations revealed an intrinsic stacking fault (ISF) along ⟨112⟩{111}, which is the partial dislocation direction for slip on these close packed planes. Though B1 structures, such as NaCl and HfC predominately slip on ⟨110⟩{110}, the ISF here is believed to facilitate slip on the {111} planes for this B1 HfN phase.
authors.affiliation: The University of Alabama, Department of Metallurgical &Materials Engineering, 245 7th Avenue 360 HM Comer Hall, Tuscaloosa, AL 35487, USA.
authors.forename: Katherine
authors.initials: K
authors.lastname: Vinson
authors.affiliation: The University of Alabama, Department of Metallurgical &Materials Engineering, 245 7th Avenue 360 HM Comer Hall, Tuscaloosa, AL 35487, USA.
authors.forename: Xiao-Xiang
authors.initials: XX
authors.lastname: Yu
authors.affiliation: The University of Alabama, Department of Metallurgical &Materials Engineering, 245 7th Avenue 360 HM Comer Hall, Tuscaloosa, AL 35487, USA.
authors.forename: Nicholas
authors.initials: N
authors.lastname: De Leon
authors.affiliation: Drexel University, Department of Mechanical Engineering &Mechanics, 3141 Chestnut Street, 115 Randell Hall, Philadelphia, PA 19104, USA.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Weinberger
authors.affiliation: The University of Alabama, Department of Metallurgical &Materials Engineering, 245 7th Avenue 360 HM Comer Hall, Tuscaloosa, AL 35487, USA.
authors.forename: Gregory B
authors.initials: GB
authors.lastname: Thompson