Basically, nitinol is a composition of nickel and titanium and it contains these two elements at amazingly equal atomic percentages. Since nickel is an allergen to many and may have contained some carcinogenic materials, the nickel content of this alloy has become the biggest issue about its applications within the medical industry. But with proper procedure and technology, this can be prevented.
What makes nickel titanium very unique is its great shape memory and super elasticity. It is simply amazing to know that the metal is capable of remembering its original shape and retains it once heated above its transformation-temperature. This occurs because of the unique crystal structures of the two elements composing this alloy. Its pseudo-elastic capacity makes it up to 30x more elastic than most metals.
Nickel titanium is available in different forms such as sheets, springs, wires, and tubes. It is considered as one of the most useful metal alloys with a lot of industrial, commercial, and medical applications. It is usually the best option for applications that need great flexibility and motion requirements. However, the biggest downtime of this alloy is the fatigue failure that it shows when used in highly demanding applications. But experts are finding ways and working hard to make it more durable and define its capacity limits.