Experimental Investigation on Mechanical Properties and Activation-recovery Performance of Fe-based Shape Memory Alloys

Abstract:

An experimental study on the mechanical properties and activation-recovery performance of hot-rolled and cold-rolled Fe-based shape memory aloys （Fe-SMA） plate was carried out and presented herein. The basic mechanical parameters and recovery stress level under different activation conditions were obtained. The results indicate that the developed Fe-SMA exhibits strong strength and excellent ductility. The average elastic modulus of hot-rolled Fe-SMA plate is 182GPa， and its tensile strength is 1136MPa， while its total elongation is 45.0%. The elasticity modulus of cold-rolled Fe-SMA plate is basically equal with that of hot-rolled plate， but its tensile strength and total elongation are relatively low. The recovery stress level of Fe-SMA obtained under different combinations of pre-tension strain and activation temperature is 165MPa~366MPa， which can meet the requirements of engineering application for crack repair of steel plates and capacity improvement of beam structures. The shape memory performance of cold-rolled Fe-SMA plate deteriorates during cold rolling process， and the cumulative effect during repeated heating activation is reduced. Compared with cold-rolled Fe-SMA， hot-rolled Fe-SMA is more suitable for structural reinforcement applications that require multiple activations to compensate for prestress loss. On the comprehensive level， the basic material properties and activation-recoverystress of Fe-SMA studied in this paper can keep pace with international product levels of Fe-SMA. However， the Fe-SMA studied in this paper is more suitable for the rehabilitation application of engineering structures due to its low cost in comparison to the international products.

Key words:Fe-based shape memory alloys;mechanical property;heating activation;recovery stress;hot rolling;cold rolling