Superelastic behavior and stabilization of stress-induced martensite in Cu-13.4Al-4.0Ni single crystals

By applying tensile stress along [100] of beta phase, the superelastic behavior and stabilization of stress-induced martensite (SIM) of Cu-13.4Al.4.0Ni(mass fraction, %) single crystals were studied. The results show that the pseudo-yield stress decreases with the increase of cycling number, and keeping load isothermally has an effect on stabilization of SIM. Previous thermal cycling between (M-s - 20 degreesC) and (A(f) + 20 degreesC) promotes the superelasticity and the stabilization of SIM as well; the pre-thermal cycling also reduces the pseudo-yield stress. However, once the stabilization of SIM is produced, it can be destabilized by either the afterwards thermal cooling-heating cycling or load and immediately unload cycling in (A(f)similar toM(d)) Isothermal treatment in (A(f)similar toM(d)) brings restabilization of SIM. The maximum superelastic value from beta --> beta (1) (18 R) is 9 % for the studied single crystal. When test temperature is in A(f)similar to (A(f) + 50 degreesC) and stress is in 0 similar to 350 MPa, the superelastic behavior exist.status: publishe