Influence of High Fluence Nitrogen Ion Implantation οn Pseudoelastic Behaviour of NiTi Shape Memory Alloy

An attempt to evaluate mechanical properties changes (superelastic phenomena) in the shape memory NiTi alloy (austenitic form) due to ion implantation ($N^{+}$, fluences of 1 × $10^{17}$ and 4 × $10^{18} cm^{-2}$) has been made. We applied the differential scanning calorimetry technique and spherical indentation (micro- and nanoindentation scale) test to study superelastic effect. The results of investigations of selected functional properties, i.e. characteristic temperatures, total and recovered penetration depth on the implanted and non-implanted NiTi samples are presented.