As critical microelectronic components are scaled down to the sub-10 nm level, they experience extreme current densities that inevitably trigger defect formation and evolution. Understanding dislocation dynamics and electro-induced damage at this particular scale is therefore crucial, as it governs the reliability of next-generation nanodevices. Herein, we investigate the dislocation evolution in Mo and Pt microcrystals upon pulse stimulation. By tracking dislocation generation, motion, and annihilation pulse-by-pulse, we reveal that enhanced electron-lattice interactions induce dislocation nucleation from sites of structural heterogeneity, in the form of dislocation loops. These dislocations experience frequent interaction and annihilation in the subsequent electropulsing process, inducing a periodic variation of dislocation density and contributing to the structural disordering. These findings not only provide insights into the structural degradation of metallic nano-interconnects during service but also have important implications for understanding the electroplasticity in bulk materials.

Sintered Nd–Fe–B magnets serve as critical components in advanced technological applications due to their exceptional magnetic properties. Nevertheless, traditional sintering processes involving high temperatures and prolonged durations often result in microstructural coarsening, thereby undermining the delicate equilibrium between magnetic and mechanical characteristics. In this study, Nd–Fe–B magnets with a relative density exceeding 99% were successfully fabricated via flash sintering under conditions of 1100 A, 1 MPa, and 1 h. The mechanism underlying rapid densification is elucidated as a synergistic interaction among electric, mechanical, and thermal fields. Specifically, the applied stress field enhances particle interface bonding, while the electric field exploits differences in inter-phase resistance to induce localized Joule heating at grain boundaries. This targeted heating facilitates the rapid liquefaction and migration of the Nd-rich phase, thereby promoting swift densification. In comparison to their conventionally pressureless-sintered counterparts, flash-sintered magnets demonstrate significant microstructural refinement, as evidenced by a 14.25% reduction in grain size and a 28.87% decrease in lattice mismatch between the grain boundary phase and the main phase. Critically, while magnetic properties are preserved, substantial improvements in mechanical properties are achieved. Specifically, Vickers hardness increases by 10.12%, fracture toughness by 41.92%, compressive strength by 59.56%, and compressive fracture strain by 15.38%. This superior overall performance is primarily attributed to the refined microstructure, uniform phase distribution, and robust interface bonding, which collectively and effectively inhibit crack propagation while maintaining magnetic isolation at grain boundaries. The findings position flash sintering as a powerful strategy for the concurrent enhancement of both magnetic and mechanical properties in Nd–Fe–B permanent magnets.

Under long-term conditions of high temperature, high pressure, and high neutron flux, reactor pressure vessel steel forms post-burst-phase Ni-Mn-Si clusters, which seriously deteriorate its mechanical properties. Eliminating Ni-Mn-Si clusters generated during service is crucial to ensuring the reliable operation of the reactor pressure vessel, which cannot be replaced. This study exploits the difference in electrical resistance between the clusters and the matrix by introducing additional free energy via a pulsed electric current to dissolve irradiation-induced Ni-Mn-Si clusters. The nanohardness of irradiated reactor pressure vessel steel increased by 2.13 GPa, and the hardness fully recovered after pulse treatment. Similarly, the number density of clusters decreased by more than 90%, and the volume fraction decreased by more than 95% after treatment. The study also found that highfrequency pulsed current is much more effective than low-frequency pulsed current in simultaneously eliminating clusters. Compared with traditional annealing treatments, this method features a shorter processing time (only 30 min), higher hardness recovery efficiency (over 90%), and a lower processing temperature. By applying a pulsed current to rearrange the internal elements of the matrix and enhance its mechanical properties, this method provides a new solution for the repair and life extension of nuclear power materials.

As a key aerospace material, 718Plus alloy exhibits Nb/Mo micro-segregation and brittle Laves phase precipitation during solidification, which seriously reduces its mechanical properties and operational reliability at elevated temperatures. This study systematically investigates the synergistic mechanism of rare earth elements and pulse current on the homogenization of 718Plus alloy, and constructs a dissolution kinetics model of Laves phase. The low La/Ce content significantly refines the dendritic structure, while excessive addition exacerbates component segregation and induces a large amount of precipitation of Laves phase. Especially, the alloy doped with 0.1874 wt% Ce showed almost complete dissolution of Laves phase and uniform distribution of Nb and Mo after pulse current treatment at 1000 degrees C for 30 min. Further analysis shows that La/Ce alters the dissolution kinetics of Laves phase by affecting diffusion related parameters, while the type and morphology of residual phase are determined by the rare earth content and compatibility with homogenization process. The results provide a plausible mechanistic interpretation for the accelerated dissolution of Laves phase under rare-earth modification and electropulsing treatment, although direct atomic-scale verification is still required.

Anti-corrosion coating with corrosion detection ability will provide more efficient protection for metal equipment. In this work, the microencapsulated filler (Ni-Co/8-HQ@DE) with both anti-corrosion and corrosion detection ability was prepared by in-situ growth and vacuum impregnation assembly technology. The load of 8HQ was determined to be 23.68 % by thermal decomposition test. The combination of test and simulation is used to quantify the ability of Ni-Co/8-HQ@DE to capture Cl- and verify the persistence of 8-HQ release. VASP simulated the reaction mechanism between 8-HQ and iron ions, and electrochemical data calculated that the thickness of the passivation film produced by 8-HQ was 3.1 nm. In addition, the impedance modulus of the prepared EP/Ni-Co/8-HQ@DE coating is three orders of magnitude higher than that of the EP coating, and the water absorption is reduced by 98.27 %. The 14 day salt spray test and 90 day salt water immersion test showed obvious corrosion detection effect.

This study systematically investigates the effect of microalloying on inclusion precipitation behavior and the evolution of mechanical properties in BISPLATE series wear resistant steels. The results show that, compared with the original BISPLATE 400, the microalloyed BISPLATE 500 exhibits significant improvements in strength and hardness, but its impact toughness decreases by 76.52% and the variance of the friction coefficient increases by a factor of 9.63, indicating a deterioration in both toughness and frictional stability. Thermodynamic calculations show that microalloying markedly increases the precipitation temperature of TiN inclusions, transforming their precipitation from solid state to mushy zone and thus leading to coarse, angular TiN and its complexes. In situ tensile tests confirm that the plastic incompatibility between these harmful inclusions and the matrix induces local stress concentration, directly leading to premature material failure. The present study therefore demonstrates that microalloying effectively enhances the strength and hardness of BISPLATE series wear-resistant steels, but at the expense of toughness and tribological stability. This contradictory performance evolution is attributed to the microalloying-induced transformation of inclusion precipitation behavior. Therefore, future microalloying design for high-performance steels should adopt an integrated strategy that rationally tailors both the metallic matrix and the inclusion system to achieve an optimal balance of strength, toughness, and wear resistance.

The upgrading and recycling of scrap metal form the foundation of the circular economy; however, these processes are often hindered by the accumulation of harmful impurities that are difficult to remove. Brass recycling is particularly restricted due to tin contamination, which can cause embrittlement. Conventional refining methods are energy intensive and subject to environmental taxes, which often result in the loss of valuable volatile elements and the inseparable removal of Sn. Herein, a synergistic strategy combining targeted alloying with a pulsed electric current is demonstrated to actively sweep and remove impurity phases from a molten metal matrix. Application of a pulsed electric current to the Sn-contaminated brass melt induces the directional migration of native Cu3Sn intermetallic phases, achieving a purification efficiency of 25.3% at an optimal frequency of 1000 Hz. Notably, the purification efficiency is considerably enhanced to 60.9% at an optimal frequency of 100 Hz by pre-alloying the melt with Ca, which transforms the impurity into Ca2Sn phases, exhibiting a larger electrical conductivity difference with the brass melt. This frequency-dependent migration behavior is attributed to the force exerted by the current-density gradient on the induced dipole of the impurity phase, a phenomenon controlled by Maxwell-Wagner interfacial polarization. These findings establish a new physical principle for active melt purification and offer a scalable, efficient, and environmentally friendly alternative to traditional pyrometallurgy for refining various complex alloys.

The detrimental effect of elemental segregation on the creep, mechanical, and fatigue properties of superalloys critically compromises their performance and reliability in extreme environments. Confronting the longstanding challenge of the inefficiency and high cost associated with conventional controlling methods, this work introduces a strategy that harnesses machine learning to guide and optimize pulsed electric current treatment for precise segregation control. The experimental results demonstrate that the application of a pulsed electric current significantly accelerates interdendritic elemental diffusion in the IN738LC superalloy by reducing the activation energy for diffusion of Ti, Ta, Nb, and C. Consequently, the segregation levels of Ti, Ta, Nb, and C are reduced by up to 61.7

In the casting of the nickel-based IN738LC superalloy, large, elongated or chain-like carbides are typical harmful phases. The traditional methods for controlling the morphology and size of carbides mainly rely on alloy composition design, cooling rate control during alloy solidification, or subsequent heat-treatment processes. However, these approaches cannot fundamentally achieve precise control over the morphology and size of carbides, thereby limiting their ability to provide uniform dispersion strengthening in superalloy. The aim of this study is to utilize the difference in electrical conductivity between the melt and carbides to apply a pulsed electric current during the solidification process of the nickel-based IN738LC superalloy, in order to obtain uniformly refined carbides. The study found that, at a cooling rate of 50℃/min, under conditions of an electropulsing frequency of 3000 Hz and a current of 160 A, the treated nickel-based IN738LC superalloy exhibited a proportion of carbides with an equivalent diameter less than 5 μm reaching 92.9

The widespread application of high-strength aluminum alloys in key fields relies on strengthening through alloying elements, which is a strategy inherently related to grain boundary element segregation, leading to stress corrosion cracking and intergranular corrosion. Consequently, understanding and controlling grain boundary element segregation is a core scientific challenge for developing advanced aluminum alloys. This study proposed a novel athermal strategy, pulsed electric current-driven defect engineering, to regulate grain boundary element segregation in aluminum alloys. Homogeneous distribution of grain boundary elements in Al-Cu alloys was achieved via the synergistic combination of pre-stretching and pulsed electric current treatment, and this microstructural regulation yields a remarkable enhancement of performance, as evidenced by the complete elimination of intergranular corrosion and a fourfold improvement in stress corrosion cracking resistance. Combined first-principles calculations and molecular dynamics simulations revealed the effects of defect, electric field, and their coupling effect on the diffusion of Cu atoms in the Al matrix. The coupling effect between electric field and defects could dramatically increase the diffusion rate of Cu atoms in the Al matrix, enabling rapid replenishment of Cu elements in the regions adjacent to grain boundaries, thereby achieving uniform element distribution at grain boundaries. This study introduces pulsed electric current-driven defect engineering as a novel strategy for modulating the elemental distribution at grain boundaries and optimizing the performance of aluminum alloys, thereby laying a theoretical groundwork for this burgeoning field.

In order to meet the stringent low-temperature impact performance requirements of 80 mm extra-thick steel plates for high-latitude marine applications, this study optimized the chemical composition by reducing noble metal additions and the carbon equivalent, and developed an innovative thermomechanical control process combined with quenching and tempering (TMCP + Q + T). The steel plate obtained through this process has a gradient microstructure, where the surface layer consists of fine grains with a high fraction of acicular ferrite, while the core is composed of a high proportion of polygonal ferrite. The tensile strength throughout the entire thickness exceeded 520 MPa, and the impact energy at -60 degrees C reached 300 J. This differentiated microstructure design of "surface fine grain strengthening and toughening plus low residual stress toughening in the core" effectively addressed the issue of non-uniform impact performance between the surface and the core of the steel plates, which not only promotes the upgrading of low-temperature equipment steel, but also provides an efficient and feasible technical solution for the low-temperature impact resistance process control of extra-thick steel plate.

A508-3 steel used for reactor pressure vessels may form microstructural defects such as dislocations during early operation, leading to an increase in the ductile brittle transition temperature of the material and thus shortening the service life of the pressure vessel. Based on the limitations of traditional annealing repair methods, which affect the expected performance due to changes in the microstructure of the material matrix caused by long-term high-temperature treatment, this study proposes the use of pulsed electric current treatment technology for multiple cycles to repair pressure vessels with degraded performance. At 85 degrees C, after pulse current treatment, the ductile brittle transition temperature of A508-3 steel subjected to secondary aging was restored to 78.6 % of the original unaged sample. The ductile brittle transition temperature of the aged sample after the second pulse current cycle repair (-106.9 degrees C) is close to that after the first pulse current treatment (-108.6 degrees C), indicating that the aging rate of the sample is delayed after pulse current repair. Under the action of pulsed current, electronic wind promotes the slip and annihilation of dislocations, thereby regenerating the properties of aged pressure vessel steel, providing a new way to extend the service life of pressure vessels.

Rare earth elements modify inclusions but generate fine particles that cause blockage of continuous casting nozzles. While pulsed electric current drives inclusions migration, the mechanism by which frequency modulates current distribution remains unclear. This study investigated inclusions migration in GCr15 rare earth steel (0-50 000 Hz) via experiments and simulations. Results reveal a non-linear frequency-efficiency relationship. An optimal frequency of 5000 Hz achieved a 62.17% removal rate by driving inclusions away from the electrode. Mechanistically, the non-uniform current field amplifies the current density difference across inclusions by 19.3 times compared to uniform current field. Consequently, there are significant differences in the migration behavior of different types of inclusions, which are positively correlated with differences in inclusion size, electrical conductivity, and projection area perpendicular to the electric current. Specifically, the migration rates show the following order: silicates > rare earth oxides > rare earth oxysulfides > manganese sulfide > simple oxides. Crucially, a geometric matching criterion is proposed: when the width of frequency-induced current density enrichment zone matches the geometric characteristic dimension of the melt, the purification efficiency reaches its maximum value. These findings offer a theoretical strategy for selecting frequency parameters based on melt geometry for deep purification.

Understanding the interactions between hydrogen and metals with different crystal structures is crucial for developing materials for hydrogen storage and transport. This study uses molecular dynamics simulations to investigate how crystal structures and defect types influence hydrogen diffusion in iron and the effect of applied electric fields. The results show that the interaction between hydrogen and defects exhibits pronounced crystallographic specificity. In body-centered cubic iron, defects act as hydrogen traps, hindering the diffusion behavior of hydrogen atoms. Conversely, in face-centered cubic iron, defects serve as fast diffusion channels for hydrogen atoms, accelerating their diffusion. Under the action of an external electric field, the diffusion rate of hydrogen atoms in iron is accelerated. Therefore, this study provides new insights and solutions for designing new materials for hydrogen energy storage and transportation from the perspectives of crystal structure, defects, and applied electric fields.

Laser cladding is the main method for preparing high-performance composite coatings. However, uneven cooling of the melt pool, as well as rapid changes in temperature gradient and cooling rate, often lead to internal coating defects and unwanted coarsening of strengthening phases, thereby limiting the improvement of surface properties. This study developed a new coating production process based on flash sintering. Through mechanical, thermal, and electrical coupling, the overall densification and uniform and stable cooling of the powder to the coating have been achieved, fully demonstrating the strengthening effect of TiC phase and achieving a strong interface bonding between the substrate and the coating. By adjusting the input current intensity of 3.2 kA, the applied load of 2 t, and the sintering time of 50 s, gradient TiC-M2 composite coating was successfully prepared. The coating has a TiC-rich surface layer of approximately 100 mu m thickness, with an ultra-high hardness of 1800 HV, and an internal TiC network reinforced by nanoscale M6C carbides, which enhances resistance to plastic deformation. The characteristics of the wavy coating-substrate interface are a low lattice mismatch of approximately 0.389% and a misorientation angle of 6.78 degrees, as well as a narrow diffusion layer of tungsten element. Due to this multi-scale gradient structure, the wear volume of the coating was reduced by 93.4% compared to the substrate. Flash sintering provides a novel and effective approach for preparing high-performance composite coatings.

Controlling the morphology of MnS inclusions is crucial for mitigating anisotropy and enhancing the performance of steels. This study introduces electropulsing treatment as a method to regulate the morphology and size of MnS inclusions. Systematic experiments conducted on non‐quenched and tempered steel reveal that electropulsing treatment facilitates the formation of spherical MnS during solidification. Under the experimental conditions of 200 Hz and 200 A, the proportion of MnS inclusions with an aspect ratio exceeding 3 significantly decreased from 26% to 9%, accompanied by a corresponding reduction in the average aspect ratio. This spheroidization phenomenon arises from the dual influence of pulsed current on both the thermodynamic and kinetic aspects of MnS precipitation. From a thermodynamic perspective, the pulsed current effectively lowers the nucleation barrier for MnS, promoting its earlier precipitation with an increased number density across a wider range of solidification fractions. Kinetically, the forced convection induced by the pulsed current not only substantially alleviates solute micro‐segregation within the interdendritic regions but also accelerates the diffusional mass transfer of Mn and S elements. This synergistic effect promotes the dispersed nucleation of MnS while effectively inhibiting its subsequent coarsening, providing novel insights into the physical microstructure control of steels.

Hydrogen embrittlement presents a significant threat to both the structural integrity and operational safety of pipeline steels employed in hydrogen transportation. Due to the thermal and mechanical gradients induced during the rolling process, X52 M steel develops a microstructural gradient across its thickness, characterized by a predominant ferrite-pearlite structure at the surface and a bainite-dominated microstructure in the mid-thickness area. This study aims to elucidate how this through-thickness microstructural heterogeneity influences the local hydrogen distribution and the propensity for hydrogen embrittlement. Multiscale characterization demonstrates that the central zone exhibits markedly higher dislocation density and localized stress concentrations compared to the surface. Consequently, this bainite-rich central region displays a 27% decrease in effective hydrogen diffusivity and a 27% increase in hydrogen trapping capacity. This enhanced hydrogen retention is primarily attributed to a 68% higher density of irreversible trapping sites, mainly situated at bainitic interfaces and fine carbide precipitates. As a result, the central region demonstrates a heightened susceptibility to hydrogen embrittlement. Collectively, these findings indicate that optimizing heterogeneous microstructures provides a promising strategy for enhancing hydrogen resistance.

At the operating temperature (∼750°C) of solid oxide cells (SOCs), Ni diffusion has been revealed to cause aging degradations on catalytic performance, electronic conductivity, and mechanical failures. This work discloses that Ni diffusion during the high-temperature (∼1400°C) SOC fabrication process can severely decrease the oxide ion conductivity due to Ni segregation (up to ∼7 at.%) at the YSZ (yttria-stabilized zirconia) grain boundaries (GBs). Combining electrochemical tests and advanced electron microscopy, we reveal that higher Ni enrichment leads to thicker space charge layer and higher space charge potential, which generates a significant GB blocking effect for oxide ion diffusion. We have quantitatively estimated the ionic conductivity drop induced by Ni segregation at the operation temperature range. Utilizing the ultrafast high-temperature sintering technique, we successfully mitigate Ni segregation at GBs, which can double the ionic conductivity at 700°C. This work not only clarifies that Ni segregation at YSZ GBs can significantly plague the ionic conductivity but also demonstrates that mitigating Ni segregation at YSZ GBs is a new avenue to reduce the cell's ohmic resistance and boost the SOC performance.

This study focused on low-carbon medium-manganese steel and utilized short-time austenitization treatment to prepare a nanosheeted FCC/BCC dual-phase structure in its pearlite matrix. However, the Mn element distribution mechanism, interface behavior, and the organization regulation mechanism of this structure still require further exploration. To this end, by combining carburizing, pearlite phase transformation, and austenitization as a coordinated regulation strategy, a controllable construction of nanoscale FCC/BCC dual-phase structure was successfully achieved in the Fe-0.2C-5Mn-1Al-0.5Si medium-manganese steel. Experimental results demonstrate that the pearlite-to-duplex phase transition is governed by austenitizing temperature and duration, with optimal parameters identified as 790 degrees C for 25 s, yielding 31.8% retained austenite. Notably, the Mn content in the FCC phase peaks at 15 wt%, while the BCC phase exhibits a gradient decrease (2-5 wt%). Elemental redistribution is dominated by interface-mediated short-circuit diffusion (diffusion distance similar to 12.5 nm). The duplex microstructure achieves a hardness of 6.63 +/- 0.65 GPa through synergistic interfacial strengthening and TRIP/RICT effects, providing theoretical insights for designing high-performance medium manganese steels.