Table of Contents
Can Nitinol be cast?
One type of friable mold casting that is particularly suitable for casting of Nitinol is investment casting. Investment casting is a highly developed process that is capable of great casting accuracy and can form extremely intricate contours.
Is Nitinol stainless steel?
In many cases, nitinol is substituted in an application which has traditionally used stainless steel. In most cases, the nitinol is substituted to take advantage of its unique superelasticity or shape memory capabilities. ** The modulus of nitinol is highly non-linear, and it is not nearly as stiff as stainless steel.
What are three properties of Nitinol?
Nitinol mechanical properties
| Young’s modulus**** | austenite | approx. 83 GPa (12E6 psi) |
|---|---|---|
| Yield strength | 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 |
What is the main property of Nitinol?
Nitinol is a metal alloy of nickel and titanium with unique properties, including superelasticity or pseudoelasticity and “shape memory” properties. That means nitinol can remember its original shape and return to it when heated. It also shows great elasticity under stress.
How do you manufacture Nitinol?
Virtually all Nitinol components go through a similar series of basic manufacturing steps. To produce the basic material forms, such as wire, tubing, ribbon, sheet and bar, Nitinol materials are vacuum-melted, hot-worked, cold-worked and then heat-treated to achieve final properties.
Is nitinol stronger than stainless steel?
At room temperature, nitinol has an ultimate tensile strength of between 103 and 1,100 MPa. By way of comparison, steel possesses a tensile strength of between 300 and 2,400 MPa, depending upon the material’s composition.
Why are braces made of nitinol?
Nitinol, also known as nickel-titanium or Ni-Ti alloy, is commonly used in orthodontics thanks to its shape memory and superelastic behaviour. We use archwires made from this clever metal alloy to move your teeth efficiently and reduce the frequency of adjustments.
Why is Nitinol used?
In medical devices, Nitinol is popular due to its biocompatibility, superelasticity and fatigue and kink resistance (5). Nitinol is used to manufacture catheter tubes, guidewires, stone retrieval baskets, filters, needles, dental files and archwires and other surgical instruments (6).
How are Nitinol stents made?
To overcome the challenge of tooling, Nitinol stents are manufactured either by laser-machining from a tube or by knitting or braiding individual wires.
Why is nitinol expensive?
Nitinol’s Unique Properties Nitinol is an especially valuable alloy because it is extremely elastic and can change shape depending on temperature.
What metal is in nitinol alloy?
Nitinol is a metal alloy of nickel and titanium with unique properties, including superelasticity or pseudoelasticity and “shape memory” properties. That means nitinol can remember its original shape and return to it when heated.
What type of alloy is nitinol?
nickel titanium alloy
Nitinol was developed by the U.S. Navy and stands for nickel titanium alloy. This metal is particularly useful for medical applications because it has thermal memory. This property allows stents to be made at a certain diameter, cooled, and then compressed onto a delivery system.
What is the austenite in Nitinol?
Nitinol typically exhibits two phases: austenite and martensite. Austenite has a body center cubic structure and is stable at higher temperatures. Martensite is a monoclinic crystal which is stable at lower temperatures (Fischer et al., 2002).
How is Nitinol manufactured?
How is nitinol formed?
In general, temperatures as low as 400 deg. C and times as short as 1-2 minutes can set the shape, but generally one uses a temperature closer to 500 deg. C and times over 5 minutes. Rapid cooling of some form is preferred via a water quench or rapid air cool (if both the parts and the fixture are small).
What is nitinol and how is it made?
like no other. When combined in just the right amounts, nickel and titanium create Nitinol.
Why is nitinol used as a stent material?
Because of its shape memory property, NiTi also are used as stents for reinforcement of blood vessels. As any other Ti alloy, NiTi displays excellent biocompatibility due to the formation of a thin titanium oxide surface. But unlike ather alloys containing Ni, Nitinol is highly stable in the body with minimal Ni release.
What is the shape memory of nitinol?
Nitinol combines two closely related unique characteristics: shape memory and superelasticity. Shape memory gives Nitinol the ability to be deformed at one temperature, and then return to its original shape when being heated to its transformation temperature.
How do I choose the best nitinol for my application?
To help you pick the Nitinol that is best for your application, at Fort Wayne Metals, we divide the categories of superelastic and shape memory into grades with stricter temperature ranges. You can click over to the superelastic or shape memory pages to learn more. Superelastic Nitinol is commonly used in medical devices.