Grain boundary configurational entropy: a challenge

Abstract

While the bulk of the high-entropy alloys is widely studied and characterized by their configurational entropy, there is a lack of general information regarding the configurational entropy of the grain boundaries. Here, we derived for the first time the basic relationships of this thermodynamic quantity related to the solute segregation at grain boundaries. Some examples of the appearance of the grain boundary configurational entropy are shown, and its effect on intergranular properties is discussed. It is stated that the role of grain boundary configurational entropy in interfacial properties is not completely clear and represents a challenge for future research.While the bulk of the high-entropy alloys is widely studied and characterized by their configurational entropy, there is a lack of general information regarding the configurational entropy of the grain boundaries. Here, we derived for the first time the basic relationships of this thermodynamic quantity related to the solute segregation at grain boundaries. Some examples of the appearance of the grain boundary configurational entropy are shown, and its effect on intergranular properties is discussed. It is stated that the role of grain boundary configurational entropy in interfacial properties is not completely clear and represents a challenge for future research.