The starting material for use in the method of this invention is a Nitinol composition consisting of 55.8+/???1.5 wt. % nickel (Ni); 44.2+/???1.5 wt. % titanium (Ti); and trace elements including iron (Fe), chromium (Cr), copper (Cu), cobalt (Co), oxygen (O), hydrogen (H), and/or carbon (C), generally less than 1 wt. %.