Processing, Properties and Applications of High-Temperature Niobium Alloys

Abstract

Niobium alloys are used in a variety of high-temperature applications ranging from light bulbs to rocket engines and nuclear reactors. The unique physical and chemical properties of these alloys have often dictated that only niobium alloys could fulfill certain application requirements. Compared to other refractory metals, niobium alloys have low density and are very ductile even at cryogenic temperatures. Most niobium alloys are also very resistant to corrosion by acids and liquid alkali metals; however, oxidation resistance at high temperatures is usually catastrophic unless protective coatings are used.

An overview of the commercial high-temperature alloys is presented. Some of the unique properties of these alloys, which require unusual processing methods and equipment, are highlighted. Important physical properties of these alloys are discussed with reference to specific applications. The needs and design restraints of these applications provide valuable insights for those developing other high-temperature materials.