COMPARATIVE THERMAL CYCLIC TESTING AND STRENGTH INVESTIGATION OF DIFFERENT BE CU JOINTS/

One of the main problems for ITER divertor target technology is to pro vide a reliable joint between Be as armour material and copper alloy h eat-sink structure. Such joints are to satisfy numerous requirements. In particular these joints should successfully withstand cyclic hear f luxes and should have good properties after neutron irradiation. To st udy such a complex problem, several investigation stages were: planned in Russia. This paper presents the results of comparative thermal cyc lic testing of different Be/Cu candidates. Summarising the thermal cyc lic test results and analysing the metallography Of those joints it wa s found that the life-time of all tested joints is limited by rather t hick brittle intermetallic layers in the bonding zone caused by relati vely long brazing time using heating and cooling down in traditional o hmic furnace. This paper thus presents attempts of using a unique braz ing technique with fast e-beam heating. Metallographic investigation a s well as X-ray spectrometric analysis of joints produced using the ne w technique were done. The recent results of testing of Be/Cu joints p roduced by fast e-beam brazing are discussed and some ideas for the ne arest future investigations are presented. (C) 1998 Elsevier Science S .A. All rights reserved.