1 Can an amorphous alloy crystallize into a high entropy alloy? Nikhil Rai, Priyabrata Das, Srikant Gollapudi  School of Minerals, Metallurgical and Materials Engineering Indian Institute of Technology Bhubaneswar, India 752050 Abstract: On the premise that amorphous-HEA composites could demonstrate high toughness and resistance to embrittlement akin to the phase separating glassy-solid solution composites, we develop a thermodynamics based approach to identify chemical compositions capable of undergoing the amorphous to HEA transformation. We introduce two new parameters called phase selection value (PSV) and molar volume dispersity parameter (Г). Using this thermodynamic approach seven multi-component compositions were proposed and the general guidelines for identifying such compositions was established. The approach also reveals that BMGs may not be as such amenable to undergo an amorphous to HEA transformation. Keywords: Amorphous; High entropy alloys; Crystallization; Phase selection; Miedema’s model We believe Amorphous-High entropy alloy (HEA) composites might provide high toughness in line with the metallic glass-solid solution composites developed by Johnson and co-workers [1,2]. Formation of intermetallics and other complex compounds during thermo mechanical processing in the supercooled region is considered as one of the causes of embrittlement of amorphous alloys [3-6]. Ductile second phases based on HEAs, which are known to bear a remarkable suite of physical properties [7-11], could provide enhanced toughness and hence the important question is, can an amorphous phase transform directly into a HEA leading to development of in situ amorphous-HEA composites. In this letter, we are proposing a thermodynamics based model for identifying compositions capable of an amorphous to HEA transformation. Herein we would like to mention that phase selection between amorphous, HEAs and intermetallics has already been investigated and reported in literature [12, 13]. However, unlike the models discussing phase selection between amorphous, HEAs and intermetallics, our investigation is focused on checking the capability of an amorphous system to crystallize into a HEA as a function of temperature. If HEAs can indeed crystallize from the amorphous phase, then the duration and temperature of phase transformation can be optimized to develop amorphous-HEAs composites with desired volume fraction of the HEA. Notwithstanding the fact that kinetics of the transformation is a key aspect,  Corresponding author Email: srikantg@iitbbs.ac.in Ph: 0091 9566288703