Amorphous phase formation in the Ni–Ti–Ta system studied by thermodynamic calculation and ion beam mixing

Abstract

The glass formation range of the Ni–Ti–Ta system was predicted by thermodynamic calculation based on Miedema's model and Alonso's method. To verify the theoretical prediction, five sets of Ni–Ti–Ta multilayered films with various compositions which were located in the predicted glass formation range were designed and the ion beam mixing was carried out to synthesize the amorphous alloys in the Ni–Ti–Ta system. It turned out that in all the five films with overall compositions of Ni72Ti21Ta7, Ni60Ti28Ta12, Ni49Ti34Ta17, Ni42Ti36Ta22, and Ni29Ti46Ta25, amorphous phases were indeed obtained, showing a good agreement between the experimental results and the thermodynamic calculation. Besides, it is expected that the Ni42Ti36Ta22 was much more favorable for the amorphous phase formation.