Superelastic behavior and stabilization of stress-induced martensite
in Cu-13.4Al-4.0Ni single crystals
in Cu-13.4Al-4.0Ni single crystals
(1. School of Materials Science and Engineering,
Harbin Institute of Technology,Harbin 150001, P.R.China;
2. Department of Materials and Chemical Engineering,
Liaoning Institute of Technology, Jinzhou 121001, P.R.China;
3. M. T. M., K. U. Leuven, de Croylaan 2, Heverlee, Belgium, 3001)
Harbin Institute of Technology,Harbin 150001, P.R.China;
2. Department of Materials and Chemical Engineering,
Liaoning Institute of Technology, Jinzhou 121001, P.R.China;
3. M. T. M., K. U. Leuven, de Croylaan 2, Heverlee, Belgium, 3001)
Abstract: By applying tensile stress along 〈100〉 of β 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 (Ms-20 ℃) and (Af+20℃) 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 (Af～Md ). Isothermal treatment in (Af～Md ) brings restabilization of SIM. The maximum superelastic value from β→β1′(18 R ) is 9% for the studied single crystal. When test temperature is in Af～(Af+50℃) and stress is in 0～350 MPa, the superelastic behavior exist.
Key words: Superelasticity； Stabilization； Stressinduced martensite; CuAlNi single crystal; Destabilization