Nitinol: Shape Memory and Superelasticity

Nitinol (Ni-Ti alloy) has shape memory and superelastic properties that make it useful for various biomedical applications.

The material’s shape memory effect allows it to return to its original geometry at a critical temperature even after significant deformation. Its superelasticity allows it to recover from large mechanical stresses without plastic deformation.

These properties are triggered by nitinol’s austenite-to-martensite transformation. This phase change does not require atomic diffusion or bond breaking, giving nitinol the ability to return to its original shape despite deformation.

Nitinol is used in self-expanding stents, which are placed inside a blood vessel to remove obstruction (like plaque buildup). Its superelasticity allows it to rotate easily and guide catheters into parts of the body that are difficult to reach.

Check out this great overview to learn more!

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