Diffusionsuntersuchungen am System Cu–Ti

As a result of diffusion studies in the binary system of Cu–Ti within a temperature range of 750°C and 850°C the intermetallic phases Ti₂Cu, TiCu, Ti₃Cu₄, Ti₂Cu₃ and Ti₂Cu₇ have been detected by means of electron microprobe analysis. Up to now according to the equilibrium diagram of Zwicker the intermetallic phase Ti₃Cu₄ was reported to be instable only. By the present investigation a time dependence of the width of the total diffusion zone as well as of each of the phases, d∼ √t, has been verified, i.e. volume diffusion is dominating. The chemical diffusion coefficients of all phases have been measured for 750°C, 800°C and 850°C. The partial diffusion coefficients for Cu and Ti in Ti₂Cu₇ for 850°C have also been determined. The chemical diffusion coefficients follow the Arrhenius law, the activation energy Q and the frequence constant D₀ could be calculated.