Tantalum-the Earth's 49th most abundant element-is frequently produced as a by-product of tin smelting. The metal is also extracted from concentrates by reduction with sodium or fused-salt electrolysis; tantalum carbide is produced by carburization of Ta 2 0 s or tantalum hydride. Sintering, electric-arc melting and electron-beam melting are used to refine and purify raw tantalum. Tantalum's unique properties make it suitable for a number of diverse applications, including capacitors, chemical equipment, hardmetal tooling and alloys. Tantalum consumption is expected to increase in the capacitor market, because of the demand for electronics equipment.
Abstract. -"Ducropur" and "Ducrolloy" -powder metallurgically produced chromium and chromium base alloys represent a unique combination of different properties: high strength at elevated temperatures and good corrosion resistance to a large variety of chemicals as well as to hot gases. The present paper shows that Ducropur is one of the most resistant materials (better than LC-Ni) in hot caustic soda applications. Furthermore, it is shown that Ducrolloy Cr44Fe5A10.3Ti0.5Y203 is almost inert to boiling concentrated nitric acid. The corrosion rate is lower than that of most HN03-resistant alloys cited in the literature. Finally, the hot air oxidationlnitridation behaviour of Ducropur can be improved by small additions of rare earth oxides and alloying with iron and aluminum. Alloys such as CrlLa203 and Cr44Fe5Al0.3Ti0.5Y2O3 form tight protective layers and are promising materials for various hot gas applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.