Devonian Palynology

Abstract

Publisher Summary Tantalum and niobium are widely used in the form of metals and alloys in the process industry, vacuum techniques, chemical machinery, surgical devices, and the automotive industry. Niobium additives are used to stabilize and improve modern stainless steels, and super alloys containing tantalum and niobium are successfully applied in gas-turbine engines and in the aerospace industry. Tantalum and niobium are added, in the form of carbides, to cemented carbide compositions used in the production of curing tools. Pure oxides are widely used in the optical industry as additives and deposits, and in organic synthesis processes as catalysts and promoters. Binary and more complex oxide compounds based on tantalum and niobium form a huge family of ferroelectric materials that have high Curie temperatures, high dielectric permittivity, and piezoelectric, pyroelectric and non-linear optical properties. The major consumer of tantalum is the capacitor production industry. About 60% of the total amount of tantalum currently produced is in the form of fine, agglomerated high-purity powder of capacitor grade. Tantalum capacitors have high volumetric efficiency and reliability.