The invention discloses a preparation method of micron-grade niobium foil, in which the niobium strip is rolled reversibly in three stages by using senjimir 20-h cold rolling machine, and the niobium foil is cleaned, edged and heat treated respectively after the reversible rolling in each stage, and finally the micron-grade niobium foil is obtained. The invention adopts Senjimil 20-roll cold rolling machine to roll niobium strip with width of 100mm ~ 120mm and thickness of 0.15mm ~ 0.2mm in three rolling stages successively. The advantages of senjimil 20-roll cold rolling machine are large rolling force and high rolling precision, and the thickness accuracy of micron-grade niobium foil is greatly guaranteed through designing reasonable rolling process. At the same time, the internal stress of niobium foil was eliminated by reasonable annealing process, and the influence of rolling process on niobium foil was reduced. Finally, niobium foil with thickness of 0.007mm ~ 0.009mm was obtained.
Niobium is a rare and refractory metal with high melting point. Because of its excellent properties, niobium foil has become a widely used high-tech material in modern industrial production and technology fields such as electronics industry, chemical industry, atomic energy industry, aerospace industry, thin film technology and superconductivity technology. Especially with the increasing demand of aviation and aerospace electrolytic capacitors, the reliability and high frequency characteristics of electrolytic capacitors are also higher requirements. Ordinary aluminum electrolytic capacitors can not fully meet the requirements of this aspect, niobium foil electrolytic capacitors with lower price than tantalum electrolytic capacitors, better performance than aluminum electrolytic capacitors, caused widespread concern in the capacitor industry in the world, and gradually become a research hotspot in the field of capacitors.
When niobium foil is rolled thinner, capacitance with smaller volume and higher specific capacity can be developed. At present, due to the limitation of rolling technology, there are mainly niobium sheet and niobium strip on the market, but there is no niobium foil with a thickness less than 10μm.
A method for preparing micron niobium foil is provided. The method uses senjimil 20-h cold rolling machine to roll niobium strip with width of 100mm ~ 120mm and thickness of 0.15mm ~ 0.2mm in three rolling stages in turn. The advantages of senjimil 20-h cold rolling machine are large rolling force and high rolling precision, and the thickness accuracy of micron niobium foil is greatly guaranteed by designing reasonable rolling process. At the same time, the internal stress of niobium foil was eliminated by reasonable annealing process, and the influence of rolling process on niobium foil was reduced. Finally, niobium foil with thickness of 0.007mm ~ 0.009mm was obtained.
