| Formation kinetics of TiNi intermetallics at the interface between Ti and Ni plate has been studied. Two types of the interfaces have been studied: Ni/Ti single-interface type; and Ti/Ni/Ti/Ni multi-interface type. After pressurization at 800℃ Ti₂ Ni and TiNi₃ form at the interface. Higher pressure promotes a more uniform and thicker reaction layer. TiNi intermetallic layer forms between Ti₂Ni and TiNi₃, growing steadily with time. Growth of TiNi satisfies the `parabolic law`, while thickness of Ti₂Ni and TiNi₃, remains nearly constant. In the case of Ti/Ni/Ti/Ni multi-layer interface, TiNi forms more effective y than that in Ti/Ni single-layer interface due to the cooperative growth of TiNi from neighbouring Ti₂Ni and TiNi₃. Thicknes measurement shows that TiNi forms by a volume diffusion mechanism at the interface. Calculated chemical diffusion coefficient, D^v is D^v=1.0014exp(-1148062/RT), and activation energy for the diffusion process is 1148062 J/㏖. |
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