Nitinol : Shape memory alloys Nickel titanium, also known as Nitinol, is a metal alloy of nickel and titanium, where the two elements are present in roughly equal atomic percentages. Different alloys are named according to the weight percentage of nickel, e.g. Nitinol 55 and Nitinol 60. Nitinol was developed by the U.S. Navy and stands for nickel titanium alloy. This metal is particularly useful for medical applications because it has thermal memory. This property allows stents to be made at a c