Tantalum wire is a wire-like tantalum material made from tantalum powder through plastic processing methods such as rolling and drawing. According to chemical purity, it can be divided into metallurgical tantalum wire (99.0% Ta purity), high-purity tantalum wire (99.0%~99.9% Ta purity), and ultra-high-purity tantalum wire (99.9%~99.99% Ta purity); according to performance, it can be divided into chemical corrosion-resistant tantalum wire, high-temperature resistant high-strength tantalum wire, oxygen-resistant brittle tantalum wire, and capacitor tantalum wire; according to application, capacitor tantalum wire can be divided into solid tantalum electrolytic capacitor lead wire, liquid tantalum electrolytic capacitor lead wire, and tantalum wire for capacitors with reliability indicators; according to state, it can be divided into soft state, semi-hard state, and hard state.
With an extremely high melting point of 2996℃, tantalum can operate stably for extended periods below 1200℃. It exhibits a low coefficient of thermal expansion and strong resistance to thermal shock. Its resistivity is approximately 13.5 μΩ·cm, making it suitable as an electrode material in electronic devices. Its density is 16.6 g/cm³, lighter than tungsten but heavier than titanium. Its tensile strength varies depending on its condition, ranging from 300-500 MPa in the annealed state to 800-1200 MPa in the cold-drawn state. Furthermore, a dense oxide film can form on the surface of tantalum wire, resisting corrosion from hydrochloric acid, sulfuric acid, nitric acid, and aqua regia. It also possesses excellent bioinertness and compatibility with human tissue.
In the electronics industry, it is primarily used as the anode lead for tantalum electrolytic capacitors, and can also be used as anode material for vacuum tubes and sputtering targets. In chemical equipment, it can be used to manufacture acid-resistant reactor linings and heat exchanger pipes. In the medical field, it can be used to manufacture orthopedic fixation wires, vascular stents, and surgical sutures. In addition, it can be used to manufacture high-temperature components such as rocket nozzle liners and high-temperature furnace heating elements. During cold working, staged annealing is required to relieve stress; argon arc welding or electron beam welding is recommended for welding. High-temperature treatment must be carried out in a vacuum or argon atmosphere to avoid oxidation. During storage, it should be placed in a sealed, dry environment, avoiding direct contact with halogens and strong alkalis.
The core performance characteristics of tantalum wire are high temperature resistance, corrosion resistance, excellent electrical and thermal conductivity, and good biocompatibility, making it a key material in many fields. A dense oxide film naturally forms on its surface, resisting strong corrosive media such as hydrochloric acid, sulfuric acid, nitric acid, and aqua regia. It does not react with most inorganic and organic acids at room temperature, exhibiting extremely high chemical stability.
The melting method is suitable for high-alloy tantalum wire or products with special performance requirements. The process involves an additional "electron beam melting + precision forging" step compared to powder metallurgy, resulting in higher costs but greater material density. In some applications, the finished tantalum wire needs to be pickled or polished to further optimize the surface oxide film quality and improve corrosion resistance or conductivity.
