Multifaceted design approaches for eutectic multi-principal element alloys

Abstract

The present thesis aims to develop multifaceted design approaches for predicting eutectic compositions prior to experimental realization in multi-principal element alloys (MPEAs). It first proposes a theoretical methodology for predicting eutectic compositions using just a pen and paper with the aid of binary phase diagrams. Acknowledging the inherent limitations of such an approach, the thesis will adopt the CALPHAD (CALculation of PHAse Diagrams) methodology to efficiently design novel eutectic MPEAs (EMPEAs), aiming to develop an alloy that can surpass the longstanding AlCoCrFeNi2.1 in terms of both design understanding and strength-ductility synergy. Moving further, the thesis will seek to identify the pseudo-eutectic compositional space and explore the quest for an invariant eutectic in MPEAs via Thermo-Calc (TC)-Python. In essence, the research presented in this thesis is anticipated to effectively establish a new frontier in the design and application of novel EMPEAs by addressing the existing research gaps in comprehending their physical metallurgy in alloy design.