The lunar polar permanently shadowed regions, rich in water ice for hydrogen production, impose a trade-off in FCC alloys: lowering stacking-fault energy (SFE) enhances hydrogen embrittlement resistance but exacerbates cryogenic discontinuous plastic flow (DPF). To address this, we designed and fabricated via additive manufacturing a compositionally graded (CoCrMn)_100−2xFe_xNi_x alloy with a single-phase FCC structure. Guided by thermodynamic calculations and first-principles predictions, the gradient-structured build exhibits spatial SFE and microstructural gradients. Quasi-static tensile tests from 298 K down to 20 K reveal significant strengthening with retained high ductility, while DPF is strongly suppressed, showing only minor stress drops. Mechanistically, the graded architecture partitions deformation: high-SFE regions promote dislocation glide and cellular substructures, whereas low-SFE regions enable planar slip and deformation nanotwinning, delocalizing strain and suppressing avalanche-like dislocation activity. Under hydrogen charging at 298 K, embrittlement resistance is preserved via a dual mechanism combining deformation-induced nanotwins and a Mn concentration gradient. This synergy balances dislocation mobility and hydrogen trapping, offering a new paradigm for simultaneous improvement of cryoplasticity and hydrogen compatibility. Our work establishes a multidisciplinary design strategy for alloys targeting extreme hydrogen and cryogenic environments.

Over the past decades, high-entropy alloys (HEAs) have been rapidly designed, developed, prepared, and tested to achieve superior performance across a multitude of applications. Computational materials science driven design techniques, including molecular dynamics, density functional theory, calculation of phase diagrams, phase-field modeling, crystal plasticity modelling, and artificial intelligence, combined with additive manufacturing and severe plastic deformation, present unprecedented opportunities to tailor microstructural features with remarkable flexibility and feasibility. This integration significantly enhances material properties. This review paper focuses on the computation-driven and processing-guided designs for structural HEAs (SHEAs), focusing on the relationship among materials, processing, microstructures, and properties. A succinct introduction to the computational design of SHEAs is first presented. Following this, we delve into the complex interplay between computational microstructures at various scales and the mechanical properties of SHEAs, revealing the underlying mechanisms. Additionally, we explore the distinctive features, advantages, and practical applications of these promising

In this work, valence electron concentration (VEC), thermodynamic calculation (CALPHAD), and first-principles method were combined to predict the phase formation of (CrMnFeCoNi)_100-xW_x (x = 0-16) HEAs. Based on the predicted results and insight, five (CrMnFeCoNi)_100-xW_x (x = 0, 4, 8, 12, 16) HEAs were prepared by experiment. The phase composition, microstructure, and mechanical properties of the selected five HEAs were studied systematically by experiment. The experimental results on the phase formation agree very well with those of the theoretical prediction. The experimental results show that the yield strength of the (CrMnFeCoNi)_100-xW_x increases by approximately three times with the addition of 16 at.% W content, while the compressive the compressive fracture strain is moderately reduced. By investigating the relationship between the phase fraction of the BCC and the yield strength as a function of W content, we conclude that the formation of the BCC phase is strongly correlated with the improvement in yield strength of (CrMnFeCoNi)_100-xW_x HEAs.

Laser additive manufacturing involves intrinsic rapid solidification rate and elemental segregation, which induce thermal residual stress and metastable microstructures, potentially leading to mechanical performance degradation. To address this, we tailored stacking fault energy (SFE) and hierarchical precipitation to enable near-full recrystallization in a Ni-based multi-principal element alloy. Guided by phase diagram calculation and density functional theory, a Ni-Cr-Fe-Co matrix with Al/Ti/V additions was designed and fabricated to stabilize a medium-level intrinsic SFE while forming hierarchical precipitates (primary BCC/B2 and secondary nanoscale acicular phases) via direct energy deposition in-situ alloying. Uniformly distributed precipitates nucleate preferentially within the grains, with limited formation at the boundaries. This microstructural change further promotes dynamic recrystallization under inherent severe plastic deformation. Consequently, the as-deposited alloy developed ∼92% recrystallized grains and exhibited a yield strength of 790 MPa, ultimate tensile strength of 1164 MPa, and uniform elongation of 24.6%, while multiscale characterizations confirmed plastic deformation interaction of precipitation within the recrystallized grains. This study demonstrates that engineering SFE and hierarchical precipitations promote dynamic recrystallization and synergetic mechanical properties, offering a generalizable strategy for additively manufactured Ni-based alloys.

The phase transformation-induced plasticity (TRIP) effect is a potent mechanism that simultaneously enhances the strength and ductility of materials. In this study, L12 precipitates were introduced into low stacking fault energy (SFE) FCC-phase TRIP-type multi-principal element alloys (MPEAs) to investigate their influence on the FCC→HCP deformation-induced phase transformation through uniaxial tensile testing at room temperature. The L12 precipitates significantly enhance the strength of the alloy. Their presence inhibits the formation and propagation of stacking faults (SFs), thereby suppressing the FCC→HCP transformation. This phenomenon arises from the combined effect of two factors. Firstly, the dispersed distribution of L12 precipitates generates high-SFE zones that segment the FCC matrix and reduce the dislocation channel width. This increases the critical stress required for the formation of the first SF loop, thereby inhibiting SFs formation, thus preventing the subsequent generation of the HCP phase. Secondly, the higher SFE of the L12 precipitates relative to the matrix causes propagating SFs to be effectively pinned, thereby restricting their motion. The present work elucidates how coherent L12 precipitates suppress the transformation process, providing a mechanistic basis for tailoring metastability in TRIP-type MPEAs through nanoscale precipitation engineering beyond conventional compositional design.

Stacking fault energies and critical resolved shear stresses (CRSSs) of different slip systems are predicted as a function of chemical composition for Mg solid solutions by accounting for chemical disorder, using the exact muffin-tin orbitals method involving coherent potential approximation and the semi-discrete variational Peierls–Nabarro model. A correlation between the stability of local atomic structure and stacking fault energies is established to understand the mechanisms behind the varied influences of alloying species. While addition of Ni, Co, Ti, and Ag (Sn, Ca, and Y) are demonstrated to significantly increase (decrease) the unstable stacking fault energy (γus) of prismatic and pyramidal 〈a〉 slip, Al, Li, and Zn yield relatively small influence. In addition, Sn, Ca, and Li decrease significantly both the intrinsic stacking fault energy (γisf) and γus of pyramidal 〈c+a〉 slip. The varied influences of alloying species on stacking fault energies of prismatic/pyramidal 〈a〉 and pyramidal 〈c+a〉 slip are demonstrated to strongly correlate with the local structural stability of the body-centered orthorhombic and triclinic structure, respectively. The counterbalance between the influence of volume change and chemical composition on the local structural stability dominates the alloying effect on γisf and γus. Furthermore, the predicted dislocation core structure and CRSSs of both basal and non-basal slips based on the calculated stacking fault energies and elastic parameters are in line with the available experimental findings. Among the studied alloying species, addition of Ca, Li, Sn, and Y are found to significantly reduce the difference of CRSS between basal and non-basal slips of Mg alloys. The present advances provide a solid basis for understanding the atomic mechanisms of plastic deformation and intelligent design of high-performance Mg alloys.

The vacancy formation is inevitable in the hydrogen storage process of medium-entropy alloys (MEAs) and high-entropy alloys (HEAs). However, hydrogen-vacancy interactions in MEA and HEA hydrides remain poorly understood. In this study, we employ first-principles calculations to investigate the energetic stability of hydrogen occupying a vacancy in Ti_0.25V_0.25Zr_0.25Nb_0.25 MEA hydride. In the defective hydride, hydrogen preferentially occupies tetrahedral interstitial (T) sites surrounding the vacancy, followed by regular T sites. Once all T sites are occupied, introducing hydrogen into the vacancy results in two distinct behaviors upon structural optimization. In one case, the hydrogen atom spontaneously migrates out of the vacancy, indicating that positions surrounding the vacancy are energetically more favorable for hydrogen occupation than the vacancy itself. In the other case, the hydrogen atom remains in the vacancy but exhibits a positive formation energy, suggesting that hydrogen is energetically unfavorable and unstable at the vacancy site. Using chemical bonding analysis, we demonstrate that the instability of hydrogen in vacancy is weakly related to the metal-hydrogen interactions. Instead, the hydrogen occupying the vacancy form strong antibonding states with nearest-neighbor hydrogen atoms, contributing to the instability. Our study provides an atomistic-level understanding of hydrogen behavior at a vacancy, enhancing the broader understanding of hydrogen storage in MEAs and HEAs.

The design and optimization of mechanically hard soft magnetic materials, which combine high hardness with magnetically soft properties, represent a critical frontier in materials science for advanced technological applications. To address this challenge, a data-driven framework is presented for exploring the vast compositional space of high-entropy alloys (HEAs) and identifying candidates optimized for multifunctionality. The study employs a comprehensive dataset of 1 842 628 density functional theory calculations, comprising 45 886 quaternary and 414 771 quinary equimolar HEAs derived from 42 elements. Using ensemble learning, predictive models are integrated to capture the relationships between composition, crystal structure, mechanical, and magnetic properties. This framework offers a robust pathway for accelerating the discovery of next-generation alloys with high hardness and magnetic softness, highlighting the transformative impact of data-driven strategies in material design.

In this study, we investigate the precipitation kinetics of Cu in 15–5 PH maraging stainless steel during high-temperature thermal treatments in the fully austenitic state. This provides direct evidence that Cu precipitation can occur in the austenite phase of martensitic or ferritic steels. The kinetics of Cu precipitation in austenite are examined at 700 and 800 °C using in situ synchrotron small-angle and wide-angle X-ray scattering, complemented by atom probe tomography investigations to analyze the precipitates, particularly their chemistry, following heat treatment. The resulting experimental data, which include the evolution of size, volume fraction, number density and chemical composition, are used to inform precipitation kinetics modelling using the Langer-Schwartz-Kampmann-Wagner (LSKW) approach coupled with CALPHAD thermodynamic and kinetic databases. The simulations accurately capture the experimental data by adjusting the interfacial energy in an inverse modelling approach. The insight that Cu precipitation occurs in austenite and subsequently in martensite paves the way for design of hierarchical structures with a bi-modal particle size distribution of Cu precipitates with varying crystal structures and compositions. Additionally, the validated LSKW modelling approach establishes a foundation for designing Cu-alloyed high-performance steels, taking into account various manufacturing routes.

Direct damage evolution simulations based on electronic structure physics show a significant correlation between Cr concentration and polymorphism in the form of localized formation of C15 Laves phase structures in Fe-Cr alloys under irradiation. We elucidate the role of Cr content in the formation and stabilization of the C15 Laves phase structure, which is crucial to understanding the behavior of materials under extreme conditions. This study also reveals a connection between non-linear magnetic behavior and irradiation-induced swelling in Fe-Cr alloys. These results advance the comprehension of radiation-induced changes in magnetization and suggest a novel experimental approach for detecting C15 clusters in irradiated Fe-Cr alloys.