Damping and transformation behaviors of Ti-50(Pd50-xCrx) shape memory alloys with x ranging from 4.0 to 5.0

摘要

The damping and transformation behaviors of Ti-50(Pd50-xCrx) shape memory alloys with x ranging from 4.0 to 5.0 are systematically investigated. The damping capacity (Q(-1)) at the martensitic transformation is found to be inversely proportional to the square root of frequency, i.e., Q(-1)alpha omega(-0.5). A relaxation peak or shoulder is observed slightly below the martensitic transformation damping peak for compositions within the compositional crossover region (4.5 = x = 4.8). Furthermore, the damping capacity at the martensitic transformation is smaller within the compositional crossover region (4.5 = x = 4.8), compared with that of compositions at both sides (x = 4.0 and x = 5.0). These observations can be ascribed to the hysteretic motion of interfaces between different phases near the compositional crossover region.