Status of international collaborative efforts on selected ITER materials

The paper presents an overview of the performance of refractory metals, ber yllium, and copper alloys, for the international thermonuclear experimental reactor (ITER) high heat flux structures. High temperature brazing, hot is ostatic pressing (HIP), friction welding, explosive bonding, and other meth ods were explored to join copper alloys to 316 stainless steel for first wa ll and limiter applications. It is concluded that the main material problem s for the ITER high heat flux components are: (a) degradation of properties after the manufacturing cycle (especially for Be/Cu and Cu/stainless steel (SS) joints); (b) helium embrittlement of Be, and Cu, and; (c) radiation-i nduced loss of fracture toughness for Be, W, and Cu alloys. (C) 2000 Elsevi er Science B.V. All rights reserved.