What is Nitinol? General Nitinol, chemistry, and trace elements requirements are defined in an ASTM standard, F2063-00. The Nitinol transformation temperatures are extremely sensitive to a small Ni or Ti concentration variation. The sensitivity increases with Ni content in the alloy. For alloys having greater than 55.0 weight percent Ni, a one weight percent deviation in Ni (or Ti) Proceedings of the International Conference on Shape Memory and Superelastic Technologies, Kunming, China, P.285-292 (2001). 2 concentration will result in approximately a 100°C shift in transformation temperatures. This extreme sensitivity requires any melting practice to tightly control the Ni and Ti ratio to meet the required tolerance in transformation temperatures.
Molten Nitinol is highly reactive and must be processed in vacuum Both vacuum induction melting (VIM) and consumable vacuum arc melting (VAR) processes are commonly used for production. Other melting processes, such as non-consumable arc, electron beam, and plasma melting, are also used in experimental scales. Graphite or calcium (CaO) crucible is preferred in the VIM process. Other crucible material, such as alumina or magnesia, contaminates the molten Nitinol with oxygen. Molten Nitinol does pick up carbon contaminants from graphite crucibles. By keeping the melting temperature below 1450°C when using a graphite crucible, the carbon content of a VIM Nitinol ingot can be controlled between 200 and 500 ppm. The transformation temperature can be controlled within +/- 5°C in a VIM ingot. To achieve more precise control, an in-situ composition control process can be implemented where samples are taken from the molten metal, and the transformation temperatures are quickly analyzed for instant composition adjustments. One also needs to bear in mind that because Nitinol transformation temperatures are so sensitive to small variations in chemistry, the analytical methods are not sufficiently accurate to predict the transformation temperature. The transformation temperature correlates much better with the charge chemistry used more reliably for ingot formulation. In the VAR process, consumable electrodes of Nitinol are melted and solidified in a water-cooled copper mold. Because there is no contamination from the crucible, cleaner materials with a carbon content of less than 200 ppm are produced. However, the molten pool of a VAR process is limited to only a small zone.
Metal Fabrication of Nitinol The Nitinol ingot is usually forged and rolled into a bar or a slab at elevated temperatures. Extrusion of Nitinol billets and tubes at temperatures between 850°C and 950°C has been experimented. Such hot working processes break down the cast structure and improve mechanical properties. Optimal hot working temperatures appear around 800°C, where the alloy is easily workable and the surface oxidation in the air is not too severe. Following hot working, Nitinol alloys are cold-worked and heat-treated to obtain final dimensions with desired physical and mechanical properties.
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 Luoyang Tongrun Nano Technology Co. Ltd. (TRUNNANO) Luoyang City, Henan Province, China, is a reliable and high-quality global chemical material supplier and manufacturer. It has more than 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 at any time.
