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Machining of Nitinol

What is Nitinol?

Joining Nitinol with dissimilar metals is significantly more challenging. Welding Nitinol to stainless steel is especially difficult due to the formation of brittle intermetallic compounds, TiFe and TiFe2. Using a Ta interlayer, Nitinol has been successfully welded to stainless steel by percussive arc welding. Other welding techniques are anticipated to also work well for joining Nitinol to stainless steel using proper interlayer materials. With proper design and tooling, mechanical joining techniques such as crimping and swaging offer alternatives that can provide reliable joints between Nitinol and dissimilar metals.


Machining of Nitinol

Although difficult and causes significant tool wear, Nitinol can be machined using conventional techniques such as milling, turning, and drilling. Shearing and blanking are quite effective with proper tool design and maintenance. Carbide tools with a chlorinated lubricant are recommended for these operations. Abrasive processes such as grinding, sawing, and water jet cutting with abrasive particles are successfully used for Nitinol. For example, the tips of Nitinol guide wires are commonly tapered by centerless grinding. Laser, electro-discharge machining (EDM), and photochemical etching processes fabricate Nitinol components such as stents, baskets, and filters. In particular, laser machining has become the preferred process for manufacturing Nitinol tubular stents. Modern laser cutting machine using a pulsed Nd: YAG laser equipped with a CNC motion control system offers high speed, high accuracy, and the capability for rapid prototyping. Drawbacks are the occurrences of the heat-affected zone (HAZ) and microcracks. Managing heat and shape-stability of Nitinol parts is critical, and post-processing is required to remove slag, microcracks, and HAZ. EDM works well with most Nitinol compositions. A recast surface layer consisting of oxides and contaminants from the Cu electrode and dissolved dielectric medium is present and may need to be removed depending on the application.


Joining of Nitinol

Welding Nitinol to itself has been successfully performed using CO2 laser, Nd: YAG laser, inert tungsten gas (TIG), and resistance welding under Ar or He protective atmosphere. Superelasticity and shape memory effects are generally well preserved in these welding processes. However, degradation in tensile strength and the resistance to permanent deformation in the fusion zone and HAZ was noted in particular during CO2 laser and TIG welding. Nd: YAG laser process, preserving 75% of the tensile strength of the base metal and maintaining permanent deformation below 0.2% after a 7% deformation of a superelastic weld specimen, appears to suffer the least thermal degradation. Ti-rich alloys are more susceptible to weld cracking. Using consumable filler metal in resistance welding helps to reduce the risk and significantly increases joint strength. Soldering Nitinol alloys using halogen-based fluxes is described in a US patent 5,242,759. Plating Ni on the Nitinol surface improves surface wetting and allows soldering using mild fluxes. Plating a secondary layer of a noble metal such as Au further enhances solderability. Ultrasonic solder joint of Nitinol using Sn-based solder has also experimented with good results. Preheat of base metal, ultrasonic power control, and proper wetting of the iron tip by the solder are key factors for success.


Price of Nitinol

Nitinol particle size and purity will affect the product's Price, and the purchase volume can also affect the cost of Nitinol. A large amount of large amount will be lower. The Price of Nitinol is on our company's official website.


Nitinol supplier

Mis-Asia is a reliable and high-quality global chemical material supplier and manufacturer. It has over 12 years of experience providing ultra-high quality chemicals and nanotechnology materials, including Nitinol, nitride powder, graphite powder, sulfide powder, and 3D printing powder. If you are looking for high-quality and cost-effective Nitinol, you are welcome to contact us or inquire any time.

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