Comparison of deformation microstructures in compression and ballistically tested tungsten single crystal rods

Micah Timothy Baquera, University of Texas at El Paso

Abstract

A comparison of microstructures associated with W single-crystal ([001], [011], [111]) rods prior to deformation (as grown), and after quasi-static compression (at a strain rate of ∼1/s) by transmission electron microscopy (TEM) shows several orders of magnitude difference in dislocation density. Dislocation substructures were not significantly different amongst the deformed sample orientations, except for that of [011]; the presence of deformation bands seen optically and by TEM was unique to this sample. In contrast, [001] W rods penetrated into steel targets, at impact velocities of ∼1.3 km/s, exhibited heavy dislocation densities, sub-grains, and dynamic recrystallization as very distinct microstructural regimes accommodating the penetration process. Twinning on {112} also occurred as a precursor to, or remnant of, these microstructures near the projectile head. These results demonstrate that deformation accommodating the extreme strains and strain rates associated with the penetration of a single-crystal rod into a metal target is not adequately represented by conventional deformation mechanisms.^

Subject Area

Engineering, Metallurgy|Engineering, Materials Science

Recommended Citation

Baquera, Micah Timothy, "Comparison of deformation microstructures in compression and ballistically tested tungsten single crystal rods" (2007). ETD Collection for University of Texas, El Paso. AAI1444085.
http://digitalcommons.utep.edu/dissertations/AAI1444085

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