كنترل رفتار استحاله و خاصيت سوپرالاستيك آلياژ حافظه دار Ti-50/3 at. %Ni تحت عمليات پيرسازي

Control of transformation behavior and superelastic property of Ti-50.3 at.%Ni of shape memory alloy via aging treatment

In the present study, the effect of aging treatment for improving superelastic property of alloy with composition of Ti-50.3 at.% Til and its influence on transformation behavior was studied. This alloy was prepared by VAR and rolling followed homogenization treatment. After solution annealing, aging treatment was carried out at 400 and 500 °C for 30 and 60 min. Three point bending test was used to investigate the superelastic behavior and transformation temperatures was determined by differential scanning calorimetry. It was found that transformation temperatures and thermal hysteresis change and multi-stage transformation appears as a result of this treatment. Also, the superelastic characteristics including level of bending stress upon loading and unloading, mechanical hysteresis, slope of plateau and amount of permanent deflection are sensitive to aging treatment. Best superelastic property was obtained by annealing treatment at 400°C for 30min.