This research is directed toward the development of materials of high stiffness and high
mechanical damping for the purpose of damping vibrations in structures and machinery. To that
end, indium-tin alloys are considered. Cast In-Sn exhibits substantial damping for a metal.
Quenching substantially improved the damping of indium-tin alloy but the effect gradually
disappeared due to aging. Cold work of 1.3 % permanent shear strain had the effect of moderately
increasing the damping of indium-tin, and 30 % permanent strain substantially increased the
damping of tin.