Published online by Cambridge University Press: 01 February 2011
TiNi shape memory alloy samples were irradiated within R-phase by 1.7 MeV electrons with different doses. The martensitic transformation temperatures were measured by Differential Scanning Calorimeter (DSC). The results indicated that the temperature M s of the onset of R-phase-to-martensite transformation decreased with increasing the dose. The electron irradiation had a slight effect on the other transformation temperatures. The second lifetime of positrons determined by Positron Annihilation Technology were lowered with an increment of the irradiated dose. Relaxation of the elastic stress fields around the Ti3Ni4 precipitates was the cause of the observed change of the transformation characteristics because of the migration and accumulation of electron irradiation-induced point defects.