Comparison of High Damping Shape Memory Alloys with Cu-Mn-Based and Fe-Cr-Based Alloys

摘要

The strain dependence and temperature dependence of damping in the thermoelastic martensitic (shape memory) alloys titanium-nickel and copper zinc aluminum was compared to predetermined optimum damping behavior in the quiet alloys copper manganese aluminum and iron chromium molybdenum. Damping measurements were taken using a modified resonant dwell technique, in which cantilever beams were evaluated for damping at their first three resonant modes at temperatures between ambient and 110 C. Differential scanning calorimetry was used to correlate microstructural changes with damping capacity. All alloys that were conditioned for high damping showed a trend of low damping at low strains, a strain threshold, and increased damping with strains above the threshold. Damping was directly related to the progress of martensitic transformation in the titanium nickel alloy. The Copper, Zinc, Aluminum alloy was examined in a condition which did not develop high damping. Damping in the Iron, Chromium, Molybdenum, alloy was insensitive to temperature change.