Abstract: Diffusion reaction of superconductig composite NbTi/Cu assembled both mechanically and metallurgically,diffusion couples Ti/Cu and Nb/Cu have/been studied by means of EPMA.The results indicate that the initial interface state of the composite NbTi/Cu significantly affects the forming process of intermetallic compounds at the interface.In comparison with the metallurgically bound composite,the intermetallic com- pounds forms at a higher temperature in mechanically bound one.Therefore.the mechanical hinding process is beneficial to the production of NbTi/Cu superconducting composite. No intermetallic compounds have been observed in Nb/Cu system.The morphology of intermetallic phases and the sequence in which they form in Ti/Cu system are somewhat different from that in NbTi/Cu.The relationship between the thickness of compound layer and annealing time obeys the rule of y~(1.5) ∝ t.

Key words: superconduetor, diffusion reaction, copper, NbTi alloy, diffusion couple