Effect of rhenium on the dislocation core structure in tungsten.
Despite exhibiting the highest melting point of all metals, the technological use of tungsten is hampered by its room-temperature brittleness. Alloying with Re significantly ductilizes the material which has been assigned to modified properties of the 1/2(111) screw dislocation. Using density functional theory, we show that alloying induces a transition from a symmetric to an asymmetric core and a reduction in Peierls stress. This combination ductilizes the alloy as the number of available slip planes is increased and the critical stress needed to start plastic deformation is lowered.
Romaner
Lorenz
L
Erich Schmid Institute of Materials Science, Austrian Academy of Sciences, Jahnstrasse 12, A-8700 Leoben, Austria. lorenz.romaner@mu-leoben.at
Ambrosch-Draxl
Claudia
C
Pippan
Reinhard
R