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Nitinol SMAs

Description

Nitinol is a metallic alloy of nickel and titanium with unique properties, including super elasticity or pseudo elasticity and "shape memory". Nitinol "remembers" its original, cold-forged shape, returning the pre-deformed shape by heating.

At higher temperatures, Nitinol has a cubic crystal structure called austenite. At lower temperatures, it spontaneously transforms into a more complex "monoclinic" crystal structure known as martensite. The temperature at which austenite transforms to martensite is generally referred to as the transformation temperature. This transformation is reversible, which means that heating to a temperature above the transformation temperature restores the crystal structure to the simpler austenite phase.

Our Nitinol SMAs

Alfa Chemistry provides a full range of Nitinol SMAs in binary and ternary formulations, and we also can produce custom formulations in binary, ternary, quaternary and beyond upon request. The following are our regular nitinol SMAs.

• Wire and Strip

  

  Nitinol Wire and Strip

  Diameter

  • 25.4 µm to 4.7 mm

  Strip

  • Width: 0.305 mm to 5.08 mm
  • Thickness: 76.2 µm to 1.016 mm
  • Spool Types

  Surface Finishes

  • Soft black oxide (chalky texture)
  • Hard black oxide
  • Oxide free (chemical etch)
  • Oxide free polished (chem etch + mechanical polish)
  • Amber oxide

  Standard Weld Wire

  • DIN 100
  • DIN 125
  • DIN 355
  • Other customer defined spools available

• Tube

  

  Nitinol Tube

  Type	OR Range	Standard Tolerance	Standard Finish
  Hypotube	0.127 – 0.508 mm	OD/ID: ± 7.6 μm	Light oxide OD – as drawn ID
  Hypotube	0.533 – 1.27 mm	OD/ID: ± 10.2 μm	Light oxide OD – oxide free ID
  Stent	1.295 – 3.81 mm	Various dependent on OD/ID finish	Combinations of light oxide and oxide free ODs & IDs
  Stent	3.835 – 5.004 mm	Various dependent on OD/ID finish	Combinations of light oxide and oxide free ODs & IDs
  Precision Tube	1.651 – 5.004 mm	OD/Wall: ± 12.7 μm	Ground OD-oxide free ID
  Precision Tube	5.029 – 8.382 mm	OD/Wall: ± 20.3 μm	Ground OD-oxide free ID
  Precision Tube	8.407 – 11.989 mm	OD/Wall: ± 25.4 μm	Ground OD-oxide free ID

  Standard	Superelastic BB
  As, Fully annealed	-25 ℃ to -5 ℃
  Af, Fully annealed	-10 ℃ to +10 ℃
  Typical UPS @ 3% stain	400 – 500 MPa
  Minimum UTS	1137 MPa
  Max. EIr, after 6% strain, Austenite	0.30%
  Min. EIu/f	10%

  * The above table represents standard properties for nitinol tube. Values may change based on OD, wall, processing, and alloy.

• Sheet

  

  Nitinol Sheet

  Typical Alloys and nominal active Af

  • As(f.a.) -25 ± 10 ℃, active Af 0 ℃
  • As(f.a.) -15 ± 10 ℃ (most common), Active Af +5 ℃
  • As(f.a.) -15 ± 10 ℃ Redox, Active Af +5 ℃
  • As(f.a.) +20 ± 15 ℃, Active Af +28 ℃
  • As(f.a.) +65 ± 20 ℃, Active Af +70 ℃
  • As(f.a.) +95 ± 5 ℃, Active Af > +80 ℃

  Size

  • Thickness – 0.076mm to 2.5mm
  • Width – up 90mm with larger sizes upon request
  • Length – up to 500mm

  Condition

  • Flat annealed (superelastic or shape memory depending on alloy)
  • Cold worked upon special request

  Surface finishes

  • Oxide (special request)
  • Etched
  • Flat ground 1.5mm and larger

• Mill Products

  

  Mill Products

  Billet and Slab

  • Condition - hot forged
  • Size - various
  • Surface finishes
    As forged oxide
    As rolled oxide
    Peeled/machined

  Plate

  • Condition - hot rolled
  • Thickness range – 3.18mm and above
  • Custom length and width, typically 300mm x 1200mm
  • Surface finishes
    Typical - sand blasted
    Optional - as rolled oxide

  Coil

  • Condition - hot rolled
  • Nominal diameters
    6.35mm, 8.38mm, 9.91mm,
    11.58mm, 14.00mm, 14.99mm
  • Surface finish – as rolled oxide

  Ring

  • Condition - hot ring rolled
  • Size - various
  • Surface finishes
    As rolled oxide
    Machined

  Bar

  • Conditions
    Hot rolled
    Hot rolled and heat treated (aged) for superelastic behavior at room temperature
  • Diameter – 12.7mm to 32mm with larger sizes upon request
  • Surface finishes
    Centerless ground
    Oxide (if heat treated)
    As hot rolled oxide
    Optional precision gun drilling

  Redraw Wire

  • Condition – as drawn with cold work up to 50%
  • Diameter range – 1.27mm to 8.89mm
  • Surface finishes
    Oxide free (pickled/etched)
    As drawn oxide

  Typically supplied on DIN 355 or weld wire spools – alternatives upon request

* Technical data included herein should be used as a guideline only, and should not be construed as maximum or minimum values for specification or for final design, or for a particular use or application. The data may be revised anytime without notice.