Abstract

Interfacial Reactions of Cu-Sn-Ti Boundary Binary Systems

Author(s): Guojun Zhou*, An H Cai and Y Luo

The Cu-Sn-Ti ternary system and its three boundary binary systems are of critical importance in practice. The Ti/Sn and Cu/Sn solid/liquid diffusion couples and the Cu/Ti diffusion couples are made and examined. Only Sn₃Ti₂ forms if Ti/Sn solid/liquid diffusion couples are annealed at 873 K for 30~160 minutes. When annealed at 808 K for 10 minutes, only Cu₃Sn forms in Cu/Sn solid/liquid diffusion couple. With the annealed time increasing, Cu₄₁Sn₁₁ layer forms between Cu and Cu₃Sn in 30 mins and then Bcc_a₂ layer forms between Cu and Cu₄₁Sn₁₁ in 60 mins. After annealing at 1023 K for 1000 hours, four compounds, CuTi₂ , CuTi, Cu4Ti₃ and Cu₄Ti form in Cu/Ti diffusion couple while Cu₃Ti₂ is absent. The interfacial reaction process and phase formation sequence has been predicted with the maximum driving force model using the thermo calc software.