A project alloy with unique shape memory was discovered by William J. Buehlerand Frederick Wang at the lab of United Stated Navy in 1958,which is Ni-Ti shape memory alloy was named Nitinol .
Why it called for nitinol?
Ni=nickel, Ti=titanium, n-o-l is code from weapon lab of United Stated Navy. Because the lab is inventor for such kind alloy, named as Nitinol.
The main alloy is 55-Nitinol,the composition include Ni 53-57% and Ti is remain.
Due to it was very difficult to melt and manufacture, and lack of funds, the potential value of nitinol wasn’t used until in the 1990s.
Shape memory effect was date back in 1932, such kind character was found from firstly gold cadmium alloy by Arne Olnader, who is researcher in Sweden. This character was found again from pinchbeck alloy at the earlier 1950s.