Influence of transition metal on glass formability of Y-TM-B (TMÂ =Â Fe, Ni) system

Semi-empirical Miedema's model was combined with the geometric one to determine glass forming ability (GFA) of ternary Y-Fe-B and Y-Ni-B systems. The enthalpies of amorphous phase and solid solution were calculated, as well as the difference between both quantities which reflects the competition during solidification. Moreover, normalized mismatch entropy and glass forming ability parameter were also determined. According to the results, yttrium plays a dominant role due to the large atomic radius and highly negative heat of mixing with the most of alloying elements. The large radii of rare earth elements have been already known to be advantageous in glassy state formation. Enthalpy contour maps for investigated alloys are similar, but significant differences in absolute enthalpy values were observed. Nickel containing system possesses the highest glass forming ability in the wide range of compositions, comparing to Y-Fe-B and Y-Co-B ones.