The Chemistry of Deformation: How Solutes Soften Pure Metals
Dallas R. Trinkle* and
Christopher Woodward
Solutes have been added to strengthen elemental metals, generating
usable materials for millennia; in the 1960s, solutes were found
to also soften metals. Despite the empirical correlation between
the "electron number" of the solute and the change in strength
of the material to which it is added, the mechanism responsible
for softening is poorly understood. Using state-of-the-art quantum-mechanical
methods, we studied the direct interaction of transition-metal
solutes with dislocations in molybdenum. The interaction increases
dramatically with increasing electron number and strongly influences
the mechanisms responsible for plasticity in these materials.
Our quantitative model explains solution softening of metals
by using changes in energy and stress scales of plasticity from
solutes.
* To whom correspondence should be addressed. E-mail: dallas.trinkle{at}wpafb.af.mil
