Nitinol Properties

Transformation Temperature -200 to 110 deg. C
Latent Heat of Transformation 5.78 cal/g

Transformation Strain
for a single cycle 8%
for 100,000 cycles 4%
Hysteresis 30 to 50 deg. C

Melting Point 1300 deg. C (2370 deg. F)
Density 6.45 g/cu.cm (0.233 lb/cu.in)
Thermal Conductivity
austenite 0.18 W/cm * deg. C (10.4 BTU/ft * hr * deg. F)
martensite 0.086 W/cm * deg. C (5.0 BTU/ft * hr * deg. F)

Coefficient of Thermal Expansion
austenite 11.0E-6/deg. C (6.11E-6/deg. F)
martensite 6.6E-6/deg. C (3.67E-6/deg. F)
Specific Heat 0.20 cal/g * deg. C (0.20 BTU/lb * deg. F)

Resistivity
austenite pprox. 100 micro-ohms * cm (39 micro-ohms * in)
martensite approx. 80 micro-ohms * cm (32 micro-ohms * in)
Magnetic Permeability < 1.002
Magnetic Susceptibility 3.0E6 emu/g

Young’s Modulus
austenite approx. 83 GPa (12E6 psi)
martensite approx. 28 to 41 GPa (4E6 to 6E6 psi)

Yield Strength
austenite 195 to 690 MPa (28 to 100 ksi)
martensite 70 to 140 MPa (10 to 20 ksi)

Ultimate Tensile Strength
fully annealed 895 MPa (130 ksi)
work hardened 1900 MPa (275 ksi)

Poisson’s Ratio 0.33

Elongation at Failure
fully annealed 25 to 50%
work hardened 5 to 10%

Hot Workability quite good
Cold Workability difficult due to rapid work hardening
Machinability difficult, abrasive techniques preferred

Nitinol data source – JM Medical