The Interface Reaction between Titanium and Iron-Nickel alloys.

The reaction zones between pure titanium and iron-nickel and pure nickel at 1173 K have been characterized. Two alloys with different initial composition were analyzed. When Ni80Fe20 is used the layer sequence at the reaction interface is: Ni80Fe20 → Ni₃Ti → NiTi → NiTi₂ →Ti, while for Ni48Fe52 the sequence is: Ni48Fe52 → Ni₃Ti → TiFe₂ → TiFe → NiTi₂ → Ti. The difference is in formation of NiTi, TiFe₂ and TiFe phases. The reaction zone remains very thin independently of time due to the fast dissolution rate of Ti in the alloy. The two different elementary chemical interaction processes have been identified in this article, namely the growth of the reaction layers by solid state diffusion and chemical conversion of the compounds by reaction-diffusion in the solid state. The mathematical description combining these processes is presented for description of the diffusion path generated during diffusion process. [ABSTRACT FROM AUTHOR]