Thermodynamic and kinetic studies of glass-forming compositions in Ca-Mg-Cu ternary metallic glasses

Abstract

Herein, we systematically studied the thermodynamic and kinetic aspects of glass forming compositions in Ca–Mg Cu alloy obtained by drawing the isocontour. Parameter PHS derived from the enthalpy of chemical mixing (ΔHchem) and normalized mismatch entropy ΔSσ/kB is used as a glass-forming ability (GFA) parameter. Variation of PHS with reported and calculated compositions is evaluated. Linear relation of Cu with PHS is observed, whereas inverse relation of Ca and Mg is obtained. The linear variation of PHS with a supercooled liquid region (SCLR) (ΔTx) is studied. Inverse correlation of critical cooling rate Rc with PHS is obtained. Rc for predicted compositions is found close to that of reported compositions. Therefore, Cu should be added carefully with other elements to improve the GFA and reduce the cooling rate of Ca‒Mg‒Cu glassy. In this paper, an empirical correlation of ΔTx with PHS is proposed, and the modeled values are found to agree with the experimental values.