Co-effect of heat and direct current on growth of intermetallic layers at the interface of Ti-Ni diffusion couples

The growth of the intermetallic layers at the interface of Ti-Ni diffusion couples was investigated under the co-effect of heat and direct current Isothermal diffusion treatments for Ti-Ni couples were conducted at 500 600 and 700 degrees C for 5 10 and 15 h with and without the passage of DC current of 10A Intensity It was found that both Ti2Ni and TiNi3 layer form at the Ti-Ni interface in all couples treated by different process but TiNi layer forms in the couples annealed above 600 C without current or at 500 C with current The growth of the whole interfacial layer shoots a parabolic relationship with time The apparent activation energy of growth for the whole interfacial layer is 83 76 kJ/mol in the couple treated by heating without a current and it decreases to 42 11 kJ/mol in the couple treated with a direct current of 10A during heating The effect of the current on the growth of different intermetallic layers vanes with its direction (C) 2010 Elsevier B V All rights reserved