Nanomechanical Behavior of CoCrFeMnNi High-Entropy Alloy

Abstract

cast, rolled, annealed, and thin-film forms. Dislocation nucleation was studied by repeated indents at a low load for each of the different processing conditions. Distinct displacement bursts (pop in) were observed in the loading curve marked by incipient plasticity for all the samples. The as-cast and annealed samples showed pop ins for 100% of the indents, whereas the rolled and thin-film samples showed a much lower fraction of displacement bursts. This was explained by the high density of dislocations for the cold-worked and thin-film conditions. The strong depth dependence of hardness was explained by geometrically necessary dislocations. The nanomechanical behavior and twinned microstructure indicate low stackingfault energy for this high-entropy alloy.

High-Temperature Nano-Indentation Creep Behavior of Multi-Principal Element Alloys under Static and Dynamic Loads

“…Here, we report the nano-indentation creep behavior of two MPEAs, namely CoCrNi and CoCrFeMnNi. These were chosen as model alloys with excellent mechanical properties [23] and a single-phase face centered cubic (FCC) microstructure [10,24]. Nano-indentation creep was studied under static and dynamic loads as a function of temperature and peak load.…”

An Overview on Fatigue of High-Entropy Alloys

“…These findings suggest that the near-threshold growth rate and fatigue threshold ∆K th of the alloy are significantly higher in a lowtemperature environment. To further investigate the impact of temperature on fatigue crack propagation [48,55,56], the fatigue crack extension experimental parameters and fatigue threshold results of several high-entropy alloys are summarized in Table 1. The comparison of the results indicates that different alloys and the same alloys at different temperatures have an impact on the final fatigue threshold and Paris coefficient [31,35,47,49,[57][58][59][60][61].…”

Size effects on plasticity in high-entropy alloys

“…An alternative approach to probe submicron scale plasticity mechanisms is using nanoindentation technique. Even though there are quite a few studies [84][85][86][87][88][89][90][91][92][93][94][95] probing nanoindentation response in HEAs, the corresponding correlation of the local deformation response to intrinsic material length scales is missing in the majority of these published studies. Nieh and co-workers 86,91 performed room temperature nanoindentation experiments on CoCrMnFeNi HEAs.…”