Nitinol Spring

Nickel Titanium (also known as Nitinol or NiTi) is in the unique class of shape memory alloys. A thermoelastic martensitic phase transformation in the material is responsible for its extraordinary properties. Nitinol alloys are typically made of 55%-56% Nickel and 44%-45% Titanium. Small changes in composition can significantly impact the properties of the material

分类:

产品描述

More Info

1.How does nitinol work? 

Nitinol Shape Memory Alloys undergo a phase transformation in their crystal structure when cooled from the stronger, high temperature from (Austenite) to the weaker, low temperature from (Martensite). This inherent phase transformation is the basis for the unique properties of these alloys – in particular, Shape Memory and Superelasticity.

Shape Memory

When shape memory alloys are in their martensitic form, they are easily deformed to a new shape. However, when the alloy is heated through its transformation temperatures, it reverts to austenite and recovers its previous shape with great force. This process is knows as Shape Memory.

The temperature at which the alloy remembers its high temperature from when heated can be adjusted by slight changes in alloy composition and through heat treatment. In the Nickel Titanium alloys, for instance, it can be changed from above +100 deg. C to below -100 deg. C. The shape recovery process occurs over a range of just a few degrees and the start or finish of the transformation can be controlled to within a degree or two if necessary.

Superelasticity

These unique shape memory alloys also show a Superelastic behavior if deformed at a temperature which is slightly above their transformation temperatures. This effect is caused by the stress-induced formation of some martensite above its normal temperature. Because it has been formed above its normal temperature, the martensite reverts immediately to undeformed austenite as soon as the stress is removed. This process provides a very springy, “rubberlike” elasticity in these alloys.

2. Nitinol shape memory sheet Surface State Options: 

♣   Black oxide surface                      ♣ As cleaned surface
♣  Medical grade polished surface  ♣  Centerless ground surface

3.  Chemical composition:

Ni: 55.4% –56.2% C≤0.07 H≤0.005 O≤0.050 N:≤ 0.05

4. Niti alloy  Standard:

ASTM F2063-05  Q/XB1516  Customer specified or Industry Standard

Alloy

Chemical

composition

Af

(Fully annealed)

Min.elongationto failure [%]

Max. Residual

elongation

after 6%

strain [%]

Main Applications

Specifications

Superelastic

Ni-Ti alloy

TiNi-SS

Ti-50.8at%

-5°C ± 5°C.

10

0.1

Eyeglass Frames, Cellular Phone Antennae, Bra Underwire

Q/XB1516.2

Q/XB1516.2

TN3

TNC

TiNiVAl

TiNiCr

-40°C ~50°C

10

0.1

Body temperature

Ni-Ti alloy

TiNi-YY

Ti-50.7at%Ni

Functional Af=33 ± 3

15

0.1

Implantable devices,Bone staples

Vascular Stents

ASTM 2063

Ti-Ni-01

55.6~55.8 wt%Ni

20 – 40

15

0.1

Guide wires, Stents

Orthodontic Arches

Q/XB1516.1

High temperature Ni-Ti alloy

Ti-Ni-02

54.8~55.5wt%Ni

45 – 95

10

0.1

Implantable active devices, Surgical tools, Thermostats Coffeepots

Q/XB1516.1

TiNiCu

TiNiCu

As-Ms ≤ 5

10

0.1

5.Nitinol Application

Shape memory Nitinol spring