Nanoindentation responses of NiCoFe medium-entropy alloys from cryogenic to elevated temperatures

NiCoFe alloy,a medium-entropy alloy,shows potential for applications in extreme environments.However,there is a theoretical barrier concerning the unclear understanding of its high-temperature dislocation motion mechanism.The load response exhibits distinct signatures relevant to thermal activation,most notably a decrease in critical force(i.e,softening)from cryogenic to elevated temperatures,e.g.,from 200 to 1000 K.The onset of plasticity is characterized by the nucleation of stacking faults and prismatic loops at low temperatures,whereas the surface nucleation of Shockley partial dislocations dominates plasticity at elevated temperatures.We show that thermal effects lead to non-uniform atom pile-ups and control the rate of phase transformation with increasing indentation depth.The findings in this work extend the understanding of the mechanical response of NiCoFe alloys under indentation at different temperatures,shedding light on the underlying dislocation motion mechanisms and surface deformation characteristics.The observed transformation-induced plasticity mechanism has implications for the properties of medium-entropy alloys and their potential applications in extreme environments.

Recent progress on high-entropy materials for electrocatalytic water splitting applications

Advanced materials for electrocatalytic water splitting applications have been sought-after considering both environmental and economic requirements.However,the traditional materials design concept limits the exploration of high-performance catalysts.The born of a materials design concept based on multiple elements,high-entropy materials,provides a promising path to break the shackles of compositional design in materials science.A number of high-entropy materials were reported to show remarkable properties for electrocatalytic water splitting applications.High-entropy materials were widely confirmed to be one kind of the best electrocatalysts for water splitting applications.Due to the synergy of multiple metal components,they show excellent catalytic activity.Several nontraditional methods were developed and reported to prepare high-performance high-entropy materials.This review article presents the recent progress on high-entropy materials for electrocatalytic water splitting applications.Moreover,it presents the research interests and future prospects in this field.