Thermal aging effects in refractory metal alloys

Space power systems are currently being envisioned that will supply from 100 kw to multi-megawatts of electrical power for advanced space systems. To meet the system requirements, operating temperatures ranging from 1100 to 1500 K have been proposed. Expected life of these space power systems are from 7 to 10 years. Because of the high operating temperatures required to obtain the desired efficiencies, refractory metals are likely candidate materials for fuel cladding, liquid metal transfer, and heat pipe applications. In particular, the alloys of columbium, and tantalum are attractive from a strength and material compatibility viewpoint. Thermal aging studies on alloys of these materials are reviewed