Grain boundary segregation and solute drag in multicomponent alloys

Grain boundary (GB) solute segregation has been proposed as a strategy to tailor the processing pathways and properties of a wide range of polycrystalline materials. Of particular interest is GB solute drag, which results when segregated solutes exert a resistive force hindering GB migration. However, we do not have a mechanistic understanding of the migration kinetics of doped GBs in multicomponent alloys, as most treatments only consider binary systems. In this work, we model GB solute drag in multicomponent alloys through theoretical and computational studies. We show that solute-solute interactions of various alloying element types result in varied GB segregation behaviors, such as synergistic cosegregation and induced desegregation, which greatly influence the characteristics of GB solute drag. Simulation results reveal that in multicomponent alloys GB desegregation can be as effective in inducing boundary solute drag. More broadly, predictions from our modeling framework motivate future research into the migration kinetics of doped interfaces, with the potential to guide the design of advanced alloys with tailored chemistries and properties. Grain boundary solute drag in multicomponent alloys remains poorly understood. The authors introduce a theoretical framework revealing diverse solute drag behaviors arising from coupled interactions of multiple dopants with migrating boundaries.