Recent advances in high-temperature niobium alloys

Nb, the lowest-density refractory metal, is of great interest for aircraft propulsion applications whose service temperatures are of the order of 1100-1150 C; the major impediment to such applications has thus far been the difficulty of fostering inherent, rather than coating-imparted oxidation resistance in Nb-base alloys. An additional impetus for Nb alloy development is the need for structural materials applicable to space nuclear power reactors, such as the SP-100 that is currently under development. Significant development has recently occurred in the use of Nb alloys as matrices reinforced by TiC particles or by W fibers.