Tantalum is a refractory metal, and the average content in the crust is about 1. 610-6%. Tantalum and tantalum alloy has high density, high melting point, corrosion resistance, excellent high temperature strength, good processing, sold ability and low plastic / brittle transition temperature, its excellent dynamic mechanical properties and oxidation surface formation after dense, stable, high dielectric constant amorphous oxide film characteristics and is widely used in electronics, chemical, aerospace, weapons and equipment and other fields. We on the characteristics of tantalum and the application of the metal chemical equipment and electronics industry.
Properties of tantalum and tantalum alloys
High purity tantalum material has excellent plasticity, and its mechanical properties are very sensitive to temperature and strain rate. At room temperature, the processing hardening degree of tantalum is very low, which can be conducted in deep cold processing, and the deformation amount of cold rolling can exceed 97%. In an inert atmosphere, tantalum and its alloys have good high-temperature mechanical properties. Adding 2.5%~10% of tungsten to tantalum can improve the strength of the material. The alloying of tantalum into an alternative continuous solid solution still maintains the core cubic crystal structure of tantalum, and also maintains the easy processing performance of tantalum material. At present, the widely used tantalum alloys mainly include Ta-2.5W, Ta-8W-2Hf, Ta W 10, TaW12 and Ta-Ta2C composites.
In chemical equipment, tantalum is used as various components, such as heat exchangers, shell and tube heaters, bayonet heaters, evaporators, condensers, thermal coupling sleeves, (blasting) safety plates, container lining, and glass container repair parts, etc. Usually, larger components are coated with a thin layer of tantalum on metal surfaces (such as steel, stainless steel and copper). Tantalum is the material selection object for the manufacture and treatment of hot and concentrated sulfuric acid equipment. Because tantalum is of considerable importance to the sulfuric acid industry, the corrosion rate is 0.05ram / a of 2l 0℃ in sulfuric acid; for the acceptable corrosion rate, the passivation performance is good at 230℃. Sulfur acid evaporator mainly uses Ta2.5W alloy, the sleeve is Ta2.5W alloy tube, tantalum tube is waste sulfuric acid and a small amount of nitric acid.
The electronics industry is the largest user of tantalum materials, and the capacitors made with tantalum have high reliability and tightness. Tantalum capacitors do not need to be fired on aluminum-coated capacitor paper, as in ordinary electrolytic capacitors, and have little inductance in themselves. Tantalum capacitors are characterized by long life, high temperature resistance, high accuracy, and excellent filter high frequency harmonic performance. Tantalum capacitors can work normally in a harsh environment with drastic temperature changes, and their small volume, large capacity, widely used in electronic computers, radar, missiles, supersonic aircraft, automatic control devices and other electronic lines.
The sealed shell of tantalum capacitors can be made by the reverse extrusion process or by tantalum chips or tantalum control. When making tantalum tubes, first cut off the pipe, and then weld the bottom cover. To produce the same performance of the product, controlling the performance of tantalum material is the key factor, not only to meet the processing requirements, but also to ensure the product quality, so there are both plastic and strength requirements in the production of capacitor sealing shell of tantalum material.
With the rapid growth of the global economy, electronics, military, chemical and other industries are about to enter a new growth cycle, the Internet, mobile Internet and China’s mechanization, automation, intelligent development trend has been determined, these will promote the demand of tantalum and tantalum alloy, make tantalum industry ushered in a period of rapid development.