Dynamic mechanical response of a Ni45.7Ti29.3Hf20Pd5 alloy

Phase transformation and damping properties of a Ni45.7Ti29.3Hf20Pd5 (at%) alloy was studied through Dynamic Scanning Calorimetry and Dynamic Mechanical Analysis techniques. Damping properties were characterized as functions of aging, temperature cycling, frequency and heating rate. The maximum damping capacity of the alloy was determined to be 0.215 during thermoelastic martensitic phase transformation, that is comparable to NiTi alloys. It was found that aging at temperatures ranging from 300 °C to 900 °C for 1.5 h was effective in controlling damping capacity of the alloy as well as altering the phase transformation temperatures. The damping capacity of the Ni45.7Ti29.3Hf20Pd5 alloy increased with heating rate and decreased with frequency.