Superelastic Nitinol's phase transformation in environments as cool as body or room temperature makes these cooler grades more common in medical devices or other lower temperature applications.
Examples of uses for superelastic Nitinol
NiTi #1 is commonly used for applications requiring superelasticity at room and body temperature. Typical applications include guidewires, stents, stylets, forming mandrels, stone retrieval baskets, and orthodontic files.
NiTi #2 is a ternary grade of Nitinol containing additions of chromium (0.2-0.3% Cr by weight) and is often used in applications requiring increased loading and unloading plateau stresses and decreased transformation temperatures.
NiTi #3 is a ternary grade of Nitinol containing additions of cobalt (1.0-2.0% Co by weight) and is often used to maximize loading and unloading plateau stresses over other Nitinol grades. Decreased transformation temperatures also allow this grade of Nitinol to remain superelastic in colder temperature applications.
NiTi #4 has the warmest transformation temperatures of our superelastic grades, resulting in decreased modulus and plateau stresses and improved fatigue performance at room and body temperatures when compared to other superelastic Nitinol grades with equivalent previous cold work and heat treatments.
NiTi #9 is the coldest grade of binary Nitinol that we offer and is used for applications requiring superelasticity at colder temperatures.
After an appropriate heat treatment, superelastic Nitinol will accommodate strain of up to 8% in tension without significant permanent deformation, when tested at room temperature which is above the transformation temperature of the material.
All Binary Nitinol grades meet the chemistry requirements set forth by ASTM F2063 for use in surgical implants.
Need something extra special?
Our unique product offerings could be just what you're looking for if the typical grades of Nitinol aren't quite right. From ultra-smooth oxide free Silk® Nitinol, to ultra-stiff USN® wire, you'll find all kinds of material solutions right here.
Mechanical properties
Nitinol offers seemingly endless possibilities. You can use the following information to learn more about superelastic Nitinol, and the markets we serve.
|
Product |
NiTi #1 | NiTi #2 | NiTi #3 | NiTi #4 | NiTi #9 | |
| Ingot Aₛ |
-35 °C to -10 °C |
-65 °C to 5 °C [-85 °F to 41 °F] |
-95 °C to -65 °C [-139 °F to -85 °F] |
-10 °C to 10 °C [14 °F to 50 °F] |
≤ -35 °C [≤ -31 °F] |
|
| Cold Worked |
||||||
| UTS |
1379 MPa |
1655 MPa [240 ksi] |
1379 MPa [200 ksi] |
1379 MPa [200 ksi] |
1379 MPa [200 ksi] |
|
|
Elongation |
> 4% |
> 4% | > 4% | > 4% | > 4% | |
|
Superelastic |
||||||
| UTS |
1241 MPA |
1378 MPa [200 ksi] |
1241 MPa [180 ksi] |
1241 MPa [180 ksi] |
1103 MPa [160 ksi] |
|
| Elongation |
> 10% |
> 10% | > 10% | > 10% | > 10% | |
| Upper Plateau |
> 483 MPa |
> 552 MPa [> 80 ksi] |
> 689 MPa [> 100 ksi] |
> 448 MPa [> 65 ksi] |
> 517 MPa [> 75 ksi] |
|
| Lower Plateau |
> 138 MPa |
> 207 MPa [> 30 ksi] |
> 414 MPa [> 60 ksi] |
> 48 MPa [> 7 ksi] |
> 172 MPa [> 25 ksi] |
|
| Active Aᶠ |
10 °C to 18 °C |
0 °C to 18 °C [32 °F to 64 °F] |
-20 °C to -10 °C [-4 °F to 14 °F] |
14 °C to 22 °C [57 °F to 71 °F] |
-10 °C to 5 °C [14 °F to 41 °F] |
|
| Notes |
Permanent set < 0.5% after strained to 8%. Results are typical for round wire diameters from 0.03 mm to 1.02 mm [0.001 in to 0.04 in]. All mechanical testing conducted at 22 °C ± 2 °C [71.6 °F ± 3.6 °F]. Please note that a correlation study may be required to switch test methods on an existing part. |
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The markets we serve
While serving medical markets is our mainstay, we have increasingly applied our Nitinol knowledge to support non-medical applications.