Recent advances and future trends in surface nanoburnishing and multifield-assisted strengthening of difficult-to-machine metal alloys: A review

Carbon-supported bimetallic RuCu catalyst for efficient hydrogen evolution from ammonia borane hydrolysis.

Metal additive manufacturing has become a powerful tool to develop customized metal alloys and to discover more advanced properties for novel extended applications. Ti-Ni based shape memory alloy is a group of intriguing smart functional materials, and adding a small amount of a third element can promote and induce more attractive functions. Due to the difficulty in traditional processing and the unique feature of material flexibility of in-situ alloying in additive manufacturing processes, not only Ti-Ni binary shape memory alloys but also Ti-Ni-X ternary shape memory alloys can be developed, manufactured, and investigated in-depth by additive manufacturing. This paper provides a brief review of the development of Ti-Ni based ternary shape memory alloys using metal additive manufacturing. The research status regarding a variety of Ti-Ni-X ternary alloys was summarized based on the classification of the two most widely used metal additive manufacturing processes: directed energy deposition and powder bed fusion. The main manufacturing issues were discussed and suggested, and the recommended research directions were made for future development.

Entropy engineered p-type Ag-alloyed CoCrFeNi metallic high entropy alloys with low lattice thermal conductivity

We propose an Au-free Ti/Al/TiN Ohmic contact on an n-type Al0.57Ga0.43N epitaxial layer and utilize it in deep-ultraviolet light-emitting diodes with improved efficiency. The surface morphology, chemical stoichiometry, and electrical performance of the proposed contact are thoroughly investigated and compared with those of conventional Ti/Al/Ni/Au electrodes. The Ti/Al/TiN stack exhibits a specific contact resistivity of 3.41 × 10-4 Ω·cm2 at optimized annealing conditions, which is 26.5% lower than that of the conventional Ti/Al/Ni/Au stack (4.64 × 10-4 Ω·cm2). A smoother surface morphology and the absence of phase separation are identified in the proposed Ti/Al/TiN design, attributed to the low diffusivity of TiN into other metal alloys and its strong thermal stability as a binary compound.

ABSTRACT Creep deformation is a dominant failure mode in metallic materials during service, governing structural stability, reliability and design life. However, conventional creep testing is time-consuming and resource-intensive, limiting the availability of high-fidelity creep data for efficient prediction. To address this issue, this study aims to develop a material-level digital twin system capable of generating high-fidelity creep strain data under limited experimental conditions. The proposed system is demonstrated using a 7-series aluminium alloy and employs a physics-guided gated recurrent unit model that integrates real-time sensor data with dynamic updating for creep strain prediction. Results show that incorporating physical constraints improves prediction accuracy by approximately 12% compared with the GRU model. Comparison with continuum damage mechanics-based creep models further demonstrated the competitive predictive capability of the proposed approach. Furthermore, a standalone application was developed to enable real-time monitoring and prediction of the creep process, facilitating efficient experimental implementation.

Electrocatalytic nitrite reduction offers a sustainable route to convert hazardous water pollutants into valuable ammonia, yet its efficiency is often stifled by the competitive hydrogen evolution reaction (HER) and sluggish kinetics. Herein, we report the rational design of a quinary alloy catalyst, Co25Cu15@NiMnMg, featuring a distorted face-centered cubic (FCC) structure for highly efficient NO2RR. By precisely tailoring the metal ratios via a sol-gel method, the electronic structure and active site distribution were optimized to break the linear scaling relations. In an alkaline electrolyte, the catalyst delivers an outstanding ammonia yield of 3528.04 μg h-1 cm-2 with a Faradaic efficiency of 96.8% at -0.5 V vs RHE, significantly outperforming most binary benchmarks. Mechanistically, in situ Fourier transform infrared spectroscopy (FTIR) and electrochemical X-ray photoelectron spectroscopy (XPS) reveal a distinct site-specific synergy: Co sites act as the primary centers for NO2- capture and hydrogenation, while Cu moieties regulate the local hydrogen environment to suppress the HER. Additionally, the Ni-Mn-Mg matrix serves as a structural scaffold to enhance conductivity and stability. This work presents a compelling "multielement synergy" strategy for developing advanced electrocatalysts, offering a dual solution for environmental remediation and green energy carrier synthesis.

Archaeometallurgical copper-artefacts contain a wide variety of metal admixtures (e.g. Pb, Bi, As, Sb, Sn) which either originate from the ores or were intentionally added. When the melt solidifies, these elements can accumulate in different structural areas and form special phases. The different alloying elements also interact with each other. In order to be able to examine these interactions, model alloys with different elements (Pb, Bi, As, Sb, Sn) and concentrations (5 or 10 wt.% each) were produced. More simple alloys show a dendritic microstructure and the added elements accumulate in the interdendritic areas. This is clearly visible for Pb and Bi additions, as both metals are not soluble in copper. As and Sb form compounds with Cu which precipitate mainly in the interdendritic regions. Sn is soluble in Cu at lower concentrations and Cu-Sn phases are formed only at higher concentrations. The resulting microstructures become very complex if more elements are involved. Finally, they enable us to have a better understanding for microstructures of ancient copper alloys.

Given the added complexity in flux calibration and composition evaluation inherent to quinary alloy growth, what motivates compounding the challenges of III–V-Bi growth with the goal of producing a quinary alloy of GaInAsSbBi for mid- and long-wave infrared sensing applications? Each elemental constituent provides some additional design freedom to achieve the ultimate goal of producing a lattice-matched, bulk random alloy mid-wave infrared III–V material with smooth surface morphology and high optoelectronic quality to enable high performance elevated operating temperatures. This paper reviews the evolution of Bi-containing semiconductor research, focusing on mid- and long-wave infrared materials and highlighting key research findings that motivated the decisions to accept the added complexity in going from binaries like InAs or InSb, to InAsBi, to InAsSbBi, and, finally, to GaInAsSbBi to meet the performance demands of advanced infrared sensing applications.

Abstract Electrodeposited Co 47.9 Fe 21.7 Sn 30.4 and Co 48.3 Fe 19.3 Cr 3.1 Sn 29.3 alloy films with thickness of 780 nm exhibited the ordered L 2 1 -type Heusler alloy structure after heat treatment at 550 ℃. Both the films exhibit soft ferromagnetic nature with saturation magnetization of ~4.5 μ B /f.u. and effective anisotropy constant of ~10 6 erg/cc at 5 K. Ab initio calculations reveal that half-metallicity is induced in Co 48.4 Fe 21.9 Sn 29.7 alloy upon substituting ~3.1 at.% of Cr in the place of Fe. The high value (~7.1 meV) of minimum excitation energy required for the majority charge carriers to transit to empty minority states through spin-flip scattering obtained from DC electrical resistivity studies supports the half-metallicity in Co 48.3 Fe 19.3 Cr 3.1 Sn 29.3 alloy films. This study showcases a promising spintronic Heusler alloy composition apart from demonstrating electrodeposition as a low-cost method for producing high quality quaternary Heusler alloy films.

Abstract This work presents a first-principles investigation of the structural, mechanical, electronic, magnetic, optical and thermoelectric properties of two quaternary Heusler alloys, CoPtMnAl and FePtMnSi. Analysis of the elastic constants confirms the mechanical stability of both alloys. Electronic-structure calculations predict robust half-metallic behaviour at the equilibrium lattice constants, characterised by 100% spin polarization at the Fermi level and an integer total magnetic moment of 5 μB per formula unit, in agreement with the Z—24 Slater–Pauling rule. The minority-spin band gaps are calculated to be 0.53 eV for CoPtMnAl and 0.52 eV for FePtMnSi. The calculated linear optical spectra indicate a metallic optical response, marked by strong low-energy screening and pronounced interband absorption in the IR and near-IR regions. FePtMnSi exhibits a more dissipative optical character, whereas CoPtMnAl is comparatively less lossy and shows slightly higher reflectivity in parts of the visible spectrum. Boltzmann transport calculations predict metallic, n-type transport for both alloys; FePtMnSi displays larger Seebeck coefficients and power-factor tendencies, while CoPtMnAl exhibits higher electrical conductivity along with increased electronic thermal conductivity. Overall, these results highlight CoPtMnAl and FePtMnSi as promising candidates for spintronic applications.

Mechanical properties and deformation mechanism of Cu–Ni–Al ternary alloys with different coherent precipitation characteristics

This study presents a first-principles investigation based on density functional theory (GGA) of the Half-Heusler compounds LiTiB and LiTiAl. Structural stability was evaluated through total energy optimization of three possible atomic configurations, with the Type-II phase identified as the energetically most favorable. Mechanical stability is confirmed by the calculated elastic constants, which satisfy the Born stability criteria. The derived mechanical parameters indicate that LiTiAl exhibits greater ductility, whereas LiTiB demonstrates higher stiffness. Both compounds exhibit metallic behavior, as evidenced by their electronic band structures and density of states. The electronic states near the Fermi level are predominantly governed by Ti d-states, while contributions from B p- or Al p-states are minor, and Li shows negligible participation. These findings indicate that LiTiB and LiTiAl are structurally stable and mechanically robust Half-Heusler metallic alloys with potential relevance for structural and functional applications.

The powder Metallurgy (P/M) method is mainly preferred in the production of superior metal alloys that cannot be produced with traditional methods. In this study, the first step was mechanical alloying (M/A) of NiTi+Lax powders via ball milling. Then the alloyed powders were pressed and gradually sintered using airtight ceramic crucibles filled with boron salt (for alloying and creating an atmospheric environment) to obtain NiTi+Lax alloys. The wear properties and behaviors of the samples were determined (with different La amounts (1wt.%, 3wt.%, and 5wt.%)) by pin-on-disc testing. The experiments were carried out at a sliding speed of 1.2 m/s and under 5N, 10N, and 15N loads. The microstructures of the worn surfaces were characterized by FESEM and the distribution of elements was analyzed by EDS. As a result, the lowest friction coefficient and wear loss were observed in the NiTi+Lax alloy containing 1wt.% La. The amount of wear volume increased with the increase in load and La content.

Elucidating plastic deformation mechanisms in γ-phase U-Mo-Zr ternary alloys using a machine-learning moment tensor potential

Percolation diagrams derived from first-principles investigation of chemical short-range order in binary alloys

High-temperature phase transformation mechanisms in the U-2.5Mo-2.5Ti-5.0Zr (U-MT5Z) quaternary alloy

A deep learning strategy to calibrate heteroatomic interactions in metal alloys

Effect of Ti content on the microstructural, mechanical and oxidation properties of ternary VNbTi refractory medium-entropy alloys

Bi/Cd synergistic engineering in quaternary TiFe alloys via feature expansion for enhanced hydrogen storage kinetics