Prediction of glass forming compositions in Al-Fe-Si alloy system by thermodynamic approach

In the present work, a thermodynamic approach based on the isometric contour is used successfully in identifying the glass forming compositions in Al-Fe-Si alloy system. Thermodynamic parameters such as enthalpy of chemical mixing (∆ Hchem), mismatch entropy normalized by Boltzmann's constant (Sσ/kB), configurational entropy normalized by Universal gas constant (Sc/R) are used for the prediction of glass forming compositions with PHS (product of ∆ Hchem with Sσ/kB) and PHSS (product of PHS with Sc/R). Total 51 compositions are identified from isometric contour. Based on the high negative value of PHSS ten best glass forming compositions are identified. Obtained results are compared with earlier studies in Al-Fe-Si and Al-TM-RE system. A linear relationship is observed between PHS and PHSS. With increasing Al content, it is observed that PHSS decreases linearly. Furthermore, it is found that tendency of variation in individual thermodynamic parameter ∆ Hchem with Sσ/kB is not acceptable approach in Al-Fe-Si system, to predict compositions in designing BMGs. Therefore, PHSS is found to be more decisive parameters when compared with other parameters for the prediction of glass forming compositions in Al-Fe-Si alloy system.