Thermodynamical properties of Zr-based bulk metallic glasses

The temperature dependence of Gibb's free energy difference (Delta G), entropy difference (Delta S) and enthalpy difference (Delta H) between the undercooled melt and the corresponding equilibrium solid phases of bulk metallic glass (BMG) forming melts has been proved to be very useful in the study of their thermodynamical behavior. The present study is made by calculating Delta G, Delta S and Delta H in the entire temperature range T-m (melting temperature) to T-g (glass transition temperature) for three Zr-based samples of BMGs: Zr57Cu15.4Ni12.6Al10Nb5, Zr41.2Ti13.8Ni10Cu12.5Be22.5 and Zr58.5Cu15.6Ni12.8Al10.3Nb2.8. The study is made on the basis of Taylor's series expansion and a comparative study is also performed between the present result and the result obtained in the framework of expansions proposed by earlier workers, and also with the experimental results. An attempt has also been made to study the glass forming ability for BMGs.