Research On Thermomechanical Training Of CuZnAl(RE) Shape Memory Alloys

The thermomechanical training of CuZnAl(RE) shape memory alloys after being treated by different heat-treatment technology was presented in this paper. The influences of different transformation temperatures, different pre-deformations, different technology of heat-treatment, different medium and temperature of thermal cycling on SME of CuZnAl(RE) shape memory alloys were studied also. In the experiment, melting happened in intermediate frequency induction furnace and composite RE(La+Ce) was added to improve the performances of the alloys. Bend method was applied to measure the SME of these alloys. Microstructure was studied by virtue of optical microscope, SEM, XRD and transmission electron microscope. The results of the experiment indicated that the SME of the alloys was favorite with transformation temperatures below 347K. The SME of the alloys was not so good with transformation temperatures beyond 361K. The SME of the alloys treated by two-grade ageing was better than that of alloys treated by grade quenching. The SME of the alloys decreased with increasing pre-deformation. The attenuation was rapid when pre-deformation was less than 2.6 percent, while the attenuation was slow when pre-deformation was more than 2.6 percent. The attenuation of two-way SME of alloys practiced in oil of 423K was less than that of alloys practiced in water of 373K.