Structural Transformations in Medium- and High-Entropy Alloy Systems in Course of High-Energy Ball Milling

Dynamics of medium- and high-entropy phase formation during the process of mechanical alloying by means of high-energy ball milling (HEBM) were studied for the equimolar CoCrFeNi, AlCoCrFeNi, and CoCrFeMnNi alloys. Using step-by-step X-ray diffraction analysis, it was found that a specific structural transformation occurs after some critical time of HEBM. It was suggested that this transformation converts nanocrystalline intermediate solid solutions formed due to severe plastic deformation during HEBM into single-phase multicomponent alloys in relatively short period of time.