Nickel Titanium alloys (nitinol or NiTi) is a superalloy consisting of approximately 55% Ni, balance Ti with minor additives.
Nitinol can exhibit a shape memory effect, where it transitions from one crystalline structure to another, and moves with substantial force in the process, upon the application of heat at a temperature specific to the alloy.
Not all nitinol exhibits the memory effect - an alternate composition, called super-elastic nitinol, shares the ability of the alloy to stretch up to 30% of its length without permanent deformation, a highly unusual characteristic for a metal.
Nexmetal corporation stocks both superelastic and shape memory nitinol in wire, sheet, and tube form. For most projects, we recommend wire as it is the least expensive and most versatile form. In comparison, sheet allows you to create 3-dimensional forms that move, and tube allows you to pump heated/cooled fluid directly through the tube for mess-free, highest efficiency activation. Nitinol can be welded in an oxygen-free environment (use shielding gas).