Niobium in high temperature applications

A critical review of the literature shows that niobium alloys have potential aerospace applications to 1316 C (2400 F) in closed cycle power systems in the uncoated state or for glide re-entry vehicles and rocket nozzles in the coated state. The survey shows that technical feasibility depends principally on controlling the oxidation and/or coating-substrate reactions as they severely degrade alloy mechanical properties. Data are presented to illustrate these instabilities and the technology developed is summarized to show how the incompatibility problems were or could be resolved. (AU)