They later found evidence that nickel titanium alloy
offered the same properties as the titanium niobium alloy.
Nitinol , or nickel titanium alloy
, offers device designers the performance characteristics of shape memory and superelasticity.
 tested the biocompatibility of Nitinol, a nickel titanium alloy
, and stainless steel as bladder implant materials.
At temperatures more than 250 [degrees]C (450 [degrees]F) above the zero-stress transformation temperature, the elastic modulus of nickel titanium alloy is 83 GPa.
If the coefficient of thermal expansion of the substrate is less than that of the nickel titanium alloy, the stress will decline more slowly during cooling.
The Essure micro-insert is constructed of a stainless steel inner coil, a dynamic outer coil made from a nickel titanium alloy
called Nitinol, which is commonly used in many medical devices and permanent implants, and a layer of polyethylene terephthalate, or polyester fibers, wound between the inner coils.
This microscopic tool is possible because some nickel titanium alloys
are what scientists call two-way shape-memory materials.