The effects of ion irradiation on NiTi shape memory alloy thin films

Thin films (2-4 mu m) of NiTi shape memory alloys were made by sputtering a nd characterized by XRD, DSC and RES. Subsequently, the films were irradiat ed by He+ ions at several doses with a view to determining the effects of s uch treatment on thin films of shape memory alloy. Both the possible degrad ation of the shape memory effect and change in transition temperature were studied. We conclude from the experiments that even at very low doses (belo w 0.01 dpa) the premartensitic transformation was affected by ion irradiati on and the characteristic temperatures were significantly lowered. (C) 1999 Elsevier Science S.A. All rights reserved.