Nitinol wire is a shape memory alloy wire composed of nickel (Nickel) and titanium (Titanium), belonging to the nickel-titanium alloy (Nitinol) series. Nitinol is widely used in many fields due to its unique shape memory effect and super elasticity. The following is a detailed introduction to Nitinol wire:
Basic composition and structure
Nitinol wire is mainly composed of approximately 55% nickel and 45% titanium. The exact ratio of nickel to titanium affects its properties. The unique properties of this alloy come from the crystal structure within the material, which can undergo a phase change when temperature or stress changes, giving the material shape memory and superelasticity.
Key features
Shape memory effect:
Nitinol wire has a shape memory effect, i.e., at a certain temperature, the alloy is able to “remember” and recover its original shape. The material can be bent or deformed arbitrarily in the cold state, and when the temperature rises to a specific range (phase change temperature), it returns to its original pre-determined shape. This property makes it valuable in applications where shape recovery is required.
Super Elasticity:
The superelasticity of Nitinol wire is demonstrated by its ability to quickly return to its original shape after large deformations without permanent deformation. Compared to conventional metals, NITI-1 wire can be deformed by as much as 8% and still return to its original shape, whereas the elastic deformation capacity of common metals is typically less than 1%. This makes the material very attractive for medical devices and other applications requiring high elasticity.
Corrosion resistance:
Nitinol wire has excellent corrosion resistance to a wide range of chemicals and environments, especially in salt water, acidic and alkaline environments. This property gives it a long service life even under harsh conditions and is widely used in medical, marine, aerospace and other applications.
Highly Biocompatible:
Nitinol wire is very popular in the medical field, especially because it is highly biocompatible and does not trigger immune reactions or toxicity in the body. Therefore, it is used in the manufacture of implants, stents, surgical sutures and other medical devices and instruments.
Excellent mechanical properties:
The material has high tensile strength and good fatigue properties, and can withstand large stresses and cyclic stresses without significant fatigue failure.
Abrasion resistance:
Nitinol wire has a high surface hardness and good wear resistance, which enables it to maintain good structural integrity during long-term use, especially suitable for applications requiring long-term use and friction.
Application Areas
Medical devices:
Cardiac stents: Nitinol wire is often used to make cardiac stents, which can be implanted into blood vessels through a catheter, utilizing the superelasticity and shape memory effect of Nitinol wire to automatically expand and support blood vessels in the body.
Orthopedic implants: such as spinal stents and joint repair materials. The shape memory effect of Nitinol wire makes the surgical procedure easier and has excellent biocompatibility.
Orthodontic wires: Nickel titanium wires are used in orthodontics due to their elasticity, which helps to correct tooth alignment and reduce patient discomfort.
Aerospace:
The light weight and high durability of Nitinol makes it an important material in the aerospace field, mainly used in the manufacture of intelligent control devices for airplanes and vibration damping systems. In addition, the shape memory function of Nitinol wire can be used for adaptive structures, such as intelligent deformation control of aircraft wings.
Industrial Engineering:
In the industrial field, Nitinol wire is widely used in precision instruments, automatic control devices and sensors. Examples include temperature control valves and smart material components in pipelines.
Its corrosion resistance also makes it suitable for equipment and components in marine environments, such as sensors or regulators in deep-sea probes.
Robotics and Intelligent Devices:
The shape memory properties of Nitinol Wires offer new possibilities for robotics, especially for the manufacture of micro-robots or deformable robot parts that can recover their shape at different temperatures and realize smart functions.
Eyeglass frames, cell phone antennas:
The high elasticity of Nitinol wire makes it ideal for eyeglass frames, which can be bent freely and do not break easily. Similarly, this material is used for cell phone antennas, which retain their function after many bends due to their flexibility and durability.
Performance parameters (common specifications)
Composition: Nickel content of about 55%, titanium content of about 45%
Phase transition temperature: Depending on the specific processing and heat treatment process, the phase transition temperature (i.e., the temperature at which the shape begins to recover) of NITI-1 is usually between 20°C and 100°C
Tensile strength: about 800~1200MPa
Maximum deformation capacity: up to 8%
Melting point: about 1310℃
