A new perspective to thermodynamical designing of high entropy bulk metallic glasses (HE-BMGs)

The present investigation involves an attempt to incorporate key thermodynamical and topological aspects of glass formation specifically the enthalpy of chemical mixing (Delta H-mix), configurational entropy (Delta S-config) and entropy due atomic size mismatch (Delta(S sigma)) into a single parameter using the P-HSS model to understand their role in designing new HE-BMG compositions. The model has been employed with 69 elements for quinary equiatomic alloys to investigate the possibilities of the alloys to form HE-BMGs. The application of the hard-sphere atomic radius in the evaluation of topological parameters through the P-HSS model appears to be insufficient in designing new HE-BMG alloy systems due to the limitations of some of the associated assumptions. Most importantly, the effect of the alteration of the local electronic environment of atoms on their atomic radii in multi-component alloys has been incorporated into the model to further establish the defining role of topology in glass formation. The results revealed that the number of quinary equiatomic alloys forming HE-BMG systems is 368,275 (3.75% of 9,818,072 (C-69(5)) total combinations). The modification in atomic radii has been found to pinpoint more precisely the HE-BMG alloy systems when compared to the hard-sphere model for atomic radii of pure elements. In a nutshell, this kind of statistical modelling approach can lead to the development of unprecedented determination of new HE-BMG compositions.