Nitinol 55

Shape memory alloy of nickel and titanium displaying superelasticity.

Core Principles & Analysis

• Its shape-memory effect was discovered in 1962 by William Buehler and Frederick Wang at the U.S. Naval Ordnance Laboratory, the source of the name NiTiNOL.
• It recovers strains of up to about 8% through a reversible martensite-austenite transformation, far beyond the ~0.5% elastic limit of ordinary metals.
• Superelastic nitinol forms self-expanding vascular stents and orthodontic archwires that exert a gentle, nearly constant force.

Specifications & Metrics

• DENSITY: 6.45 g/cm³
• YIELD STRENGTH: 560 MPa
• HARDNESS: 89 HRB