High-velocity deformation of Al0.3CoCrFeNi high-entropy alloy: Remarkable resistance to shear failure

Abstract

The mechanical behavior of a single phase (fcc) Al0.3CoCrFeNi high-entropy alloy (HEA) was studied in the low and high strain-rate regimes. The combination of multiple strengthening mechanisms such as solid solution hardening, forest dislocation hardening, as well as mechanical twinning leads to a high work hardening rate, which is significantly larger than that for Al and is retained in the dynamic regime. The resistance to shear localization was studied by dynamically-loading hat-shaped specimens to induce forced shear localization. However, no adiabatic shear band could be observed. It is therefore proposed that the excellent strain hardening ability gives rise to remarkable resistance to shear localization, which makes this material an excellent candidate for penetration protection applications such as armors.

Fundamental understanding of mechanical behavior of high-entropy alloys at low temperatures: A review

“…2. 26 However, Li et al 27 reported an obvious strain-rate dependence in the Al 0.3 CoCrFeNi HEA (the grain size of ;500 lm) with the strain rate varying form 10 À4 to 1800 s À1 . As presented in Figs.…”

“…As presented in Figs. 3(a) and 3(b), 27 the compressive true stress-strain curves and the corresponding strain-rate sensitivity, which is defined as log r y = log _ e (r y is the yield stress and _ e is the strain rate), are plotted, where the pure Al is used for comparison. As they stated, the strain-rate sensitivity is ;0.053, which is about two times higher than that of the pure Al, i.e., ;0.028.…”

“…As they stated, the strain-rate sensitivity is ;0.053, which is about two times higher than that of the pure Al, i.e., ;0.028. 27 They also studied the thermal softening of the Al 0.3 CoCrFeNi HEA at a high strain rate of 1800 s À1 , as plotted in Fig. 3(c).…”

“…17 Recently, there are research activities on the performance of HEAs under low temperatures (below room temperature), such as the CoCrFeMnNi HEA. 16,[22][23][24][25][26][27][28] It is interesting to find that the CoCrFeMnNi HEA shows a great temperature dependence on its tensile yield strength below room temperature. 26 What's more important is that the tensile yield strength and ultimate strength, as well as the ductility, are dramatically increased as the temperature reduced from 293 to 77 K. These studies on the low-temperature properties of HEAs give us a new understanding in this area and may provide a great potential on the cryogenic applications of HEAs, such as cryogenic containers and outer space probes.…”

Application of Nano High-Entropy Alloys to Reduce Energy Consumption and Wear of Copper Oxide and High-Grade Iron Ores in Heavy Mining Industries—A Case Study

“…High-entropy alloys [3,[19][20][21][22] and high-entropy nano-alloys [23,24] have not been used as a practical coating in the mineral industry in any form so far. The extraordinary characteristics of high-entropy alloys in can be made us of in heavy industries [25][26][27][28][29][30][31][32][33][34][35][36][37] to produce unique compositions [38][39][40][41][42][43][44][45] and their behaviors and properties [46][47][48] can be manipulated to introduce innovative alternatives, such as filler metals [49], which are hard-facing [50][51][52] and wear resistant [53] to increase to shear failure, high cavitation erosion, and corrosion [54,55]. In general, the impact strength of hardened alloys decreases with increasing carbide content.…”