Modeling and Analysis of Yielding and Strain Hardening in Metastable High‐Entropy Alloys

Abstract

Metastable dual‐phase high‐entropy alloys (HEAs) have become an attractive paradigm as structural materials due to their outstanding mechanical properties compared with single‐phase HEAs, which originate from the multiple strengthening mechanisms. Herein, a theoretical model is established by integrating the effects of lattice distortion, dislocation, grain boundary, and phase transformation, to study the mechanical responses of metastable HEAs during uniaxial tensile deformation. The results show the contribution of various mechanisms to the strength, and strain hardening can be determined quantitatively. In particular, the face‐centered cubic (FCC) to body‐centered cubic (BCC) phase transformation would dominate the flow stress with plastic strain to exceed 6%, due to the strong phase interface strengthening and the formation of hard BCC phase. This work provides a microstructure‐based constitutive model for predicting the flow stress and strain hardening properties of metastable HEAs.

A Focused Review on Engineering Application of Multi-Principal Element Alloy

“…By adjusting the alloy composition, such as reducing the content of Co and Ni and Mn, to reduce the room temperature and low-temperature stability of the FCC phase, the deformation-induced transformation-strengthening can occurs in the MPEA, resulting in very considerable strengthening and plasticizing effect (Bae et al, 2018;Fang et al, 2019;Li et al, 2016;Ren et al, 2021) (Figure 2A). Transformation induced plasticity (TRIP) includes FCC→HCP and FCC→BCC.…”

Formation and Anisotropic Mechanical Behavior of Stacking Fault Tetrahedron in Ni and CoCrFeNiMn High-Entropy Alloy

“…Dai and Victoria (2011) proposed that the forming ability of SFT is closely related to the stacking fault energy (SFE): the lower the SFE, the easier the SFT is to form. High-entropy alloys (HEAs), as a new type of high-performance alloy, have attracted considerable attention due to their excellent mechanical properties and designability (Li et al, 2018;Feng et al, 2020;Luo et al, 2021;Peng et al, 2021;Ren et al, 2021). The SFEs of FCC HEAs are usually low (Huang et al, 2015;Chandan et al, 2021), and are even of negative values (Zhao et al, 2017), indicating that SFTs would form more easily in HEAs than in conventional alloys.…”