Reliable joining of high-entropy carbide ceramics (HECCs) to high-temperature alloys is urgently needed for engineering applications in high-temperature structural fields. In this work, (VNbTaMoW)C and Inconel 600 nickel-based alloy were successfully brazed using BNi-2 filler metal (Ni-7Cr-4.5Si-3B-3Fe, at%). The interfacial reaction mechanism dominated by Cr and B under the high-entropy effect was clarified. The joint exhibited a multilayered and stable transition structure composed of HECC substrate, a high-entropy reaction phase of (Cr, V, Nb, Ta, Mo, W)(B, C), Cr3C2, Cr2B, Ni(s, s), Cr23C6, CrB, Cr7C3, and the Inconel 600 substrate. The nickel-based solid solution was mainly precipitated and locally enriched along grain boundaries, relieving the interfacial residual stress. The shear strength remained above 130 MPa over a wide processing window, reaching 219 MPa at room temperature and 320 MPa at 800 ℃. These properties were attributed to the stable interfacial structure and stress-relaxation effect of the nickel-based solid solution.

Traditional methods to reduce welding hydrogen-induced cracking (HIC) in ultra-high-strength steel (UHSS) rely on pre- or post-weld heat treatment to facilitate hydrogen diffusion. This work proposes a heat treatment-free strategy to reverse the hydrogen diffusion path using designed low-transformation-temperature (LTT) welding materials. In conventional ER140S-welded joints, the weld metal (WM) phase transformation temperature at 479 degrees C exceeds the 407 degrees C of the heat-affected zone (HAZ), creating a "hydrogen adsorption temperature window" (HATW). This HATW drives intense hydrogen accumulation in the HAZ, where the observed hydrogen bubble area fraction reaches 13.1% compared to 18.6% in the WM. Correspondingly, the simulated HAZ hydrogen concentration accumulates to 2.05 ppm, exceeding the 1.69 ppm retained in the WM. This severe enrichment results in a lower critical stress (LCS) of 347 MPa and an embrittlement index (EI) of 0.25. This study designed an LTT welding material with a transformation temperature of 171 degrees C, establishing a "negative hydrogen adsorption temperature window" (NHATW). This NHATW enables hydrogen back-diffusion from the HAZ into the WM, restricting the observed HAZ bubble fraction to only 0.4% against 11.3% in the WM, and suppressing the HAZ concentration to 0.44 ppm compared to 2.58 ppm confined within the WM. Furthermore, the 10.8% retained austenite in the designed LTT WM effectively reduces diffusible hydrogen. The synergistic effect elevates the LCS by 81.8% to 631 MPa and the EI by 88.0% to 0.47, providing a reliable heat treatment-free welding solution for UHSS.

Residual stress generated during laser powder bed fusion (LPBF) fabricating of thin-walled Ti-6Al-4V can adversely affect the performance of products, and annealing heat-treatment is a common solution to address this issue. The mechanisms governing stress evolution and the stress-strain interaction during LPBF fabricating and annealing of titanium alloy thin-walled structures remain to be elucidated. Therefore, this work conducts thermo-mechanically coupled numerical simulation and microstructural characterization for thin-walled Ti-6Al-4V during the LPBF fabrication and stress-relief annealing process. Stress and strain evolution during annealing at 650 degrees C is calculated and analyzed, with experimental validation through XRD residual stress testing. Furthermore, principal component analysis is employed to quantitatively assess the relationships between the evolving stress and the contributing strains (thermal, plastic, and creep) during annealing, concluding that thermal strain dominates stress evolution while creep strain becomes increasingly influential over time. Compared to as-built, the microstructure of thin-walled Ti-6Al-4V remains predominantly alpha ' martensite in stress-relieved, whereas lattice distortion is reduced. Thermal activation process of annealing promotes the recovery and coarsening of alpha ' martensite, and decreasing the average geometrically necessary dislocation density from 3.026 & times; 1015 m-2 to 1.984 & times; 1015 m-2, thereby releasing stress. This study will offer a mechanistic guidance toward the shape controlling, property tailoring and process optimization of titanium alloy thin-walled structures fabricated by LPBF.

Plasticity plays a key role in diffusion bonding process, while the fundamental mechanism by which plasticity affects the diffusion bonding process remains unclear, hindering the further advancement of the diffusion bonding technology. In this work, Zr-4 alloys with various plasticity were obtained through hydrogenation first and subsequently diffusion bonded at identical temperature and pressure. The high-temperature plasticity of the Zr-4 alloy were improved after hydrogenation, accompanied by increased interface bonding ratios and shear strengths of the diffusion-bonded joints. Meanwhile, EBSD images proved that a ~110% increase in recrystallization happened with the increase of the hydrogen content. MD simulation was conducted and the results further confirmed that hydrogen-induced generation of β-Zr with better plasticity indeed exhibited lower compressive yield strength than α-Zr at diffusion-bonded temperatures. Therefore, the β-Zr underwent rapid dynamic recrystallization within only 0.5ns, while α-Zr failed to recrystallize even after 2 ns at the same load. A notable stress-strain curve fluctuation was detected for the hydrogenated Zr-4 samples tested at 700℃, further indicating that an in-situ dynamic recrystallization indeed happened during the diffusion bonding process. The strong recrystallization finally facilitated the formation and growth of grains at the bonding interface. This work revealed that improving the intrinsic plasticity of the Zr-4 substracts via hydrogen-induced phase transformation, without changing the temperature and pressure, effectively enhanced the dynamic recrystallization of the substracts, thereby improving interface bonding ratio and overall mechanical performance of diffusion-bonded joints, providing new insights on improving the diffusion bonding quality in addition to the common process parameter optimizations.

Manganese-based oxides, demonstrating exceptional catalytic performance in NH3-selective catalytic reduction of NO below 200 °C, are considered a promising solution in the field of low-temperature catalysis. However, their excessive dehydrogenation activity can cause NH3 to be converted into the undesired byproduct N2O, thereby limiting their application. Here, we employed density functional theory (DFT) calculations to investigate the inhibiting mechanism of N2O formation through single 3d transition metal doping (Sc, Ti, V, Cr, Fe, Co, Ni, and Cu) on MnO2. At the Mn active site, the d orbitals split into five non-degenerate localized electronic states, and the pz orbital of NH3 preferentially couples with the dz2 orbital to achieve the most stable adsorption. Based on this selective orbital coupling behavior, we identified that the energy level of the dz2 orbital center is a dominant factor in N2O formation, and we also elucidated how the energy barrier of N2O formation can be tailored by modulating the energy alignment between the pz and selected dz2 orbitals, which exhibits a volcano plot relationship. Our work not only reveals the adsorption characteristics of selective orbital coupling in doped MnO2 but also uncovers the role of d-d orbital hybridization in inhibiting N2O formation.

Copper-steel is a typical bimetal structure that merges the superior ductility of copper alloys with the high strength and hardness of steel. However, the significant differences in physical and chemical properties between copper and steel make interfacial cracks highly prone to formation, hindering the development of copper-steel bimetal materials. In this work, CuCrZr was deposited on a 25Cr2Ni4MoV substrate using the direct energy deposition method. The interfacial cracks generated by Cu diffusion into the grain boundaries of 25Cr2Ni4MoV were successfully eliminated by introducing an IN625 interlayer. Micro-diffusion takes place at the 25Cr2Ni4MoV-IN625 interface along the grain boundaries of 25Cr2Ni4MoV, generating interfacial pinning effects. Liquid phase diffusion occurs at the CuCrZr-IN625 interface, resulting in a fusion layer within the IN625 interlayer. The continuously precipitated Ni-Cr-Mo phase forms an incoherent structure with the fusion layer, which becomes a crack propagation path during tensile loading. No layer separation was observed at the horizontal fracture interface between IN625-steel and IN625-CuCrZr, with horizontal strains of 11% and 24%, respectively, significantly higher than the 5.5% recorded for CuCrZr-steel. These findings underscore the importance of regulating the interface in copper-steel bimetallic materials.

Low-temperature ammonia-selective catalytic reduction (NH3-SCR) over MnO2 is attractive for nitrogen oxides (NOx) abatement yet is intrinsically penalized by nitrous oxide (N2O) formation, a potent greenhouse byproduct. Here, we show that oxygen-site nonmetal substitution in β-MnO2 can simultaneously suppress N2O and accelerate NH3-selective SCR, enabled by a feasibility-to-mechanism computational workflow. Screening by structural compatibility, orbital hybridization, thermochemical and kinetic stability identifies viable dopants, among which F and S most effectively rewire reaction branching. Kinetics estimated by the density functional theory calculations reveal that F and S raise the N2O-forming rate-determining barrier from 0.80 eV to 0.93/0.92 eV, while lowering the N2-forming barrier from 0.48 eV to 0.40/0.42 eV. At 200°C, F- and S-doped β-MnO2 increase TOF by a factor of 8.40 and 4.24, respectively, and enhance kinetic N2 selectivity by a factor of 1.66 and 1.38, respectively. We identify Mn(d)-nonmetal(p) band center alignment as a mechanistic descriptor that points to a volcano-like trend for the energy barriers of N2O and N2, supported by Bader charge, COHP/ICOHP, and ELF analyses. These results serve as a theoretical design reference for tuning the activity-selectivity trade-off in oxygen-site-modified oxide SCR catalysts.

Pyrolysis and coking of aviation fuels under high-temperature conditions are critical to the performance and longevity of aero-engines. Reactive force field molecular dynamics (ReaxFF MD) was used to investigate the atomic-scale pyrolysis and coking behavior of a four-component RP-3 surrogate fuel and the inhibitory effects of methanol (CH3OH) and ammonia (NH3) additives. Results showed that pyrolysis was initiated via C-C bond cleavage in alkanes and cycloalkanes, followed by radical-mediated chain elongation and cyclization into polycyclic aromatic hydrocarbons (PAHs), forming layered coke structures. Methanol suppressed coke formation by generating OH radicals that intercept unsaturated intermediates, while ammonia introduced C-N species (e.g., HCN) that hinder PAH growth through nitrogen-doped ring formation and carbon chain shortening. Notably, NH3 exhibited superior inhibition, reducing the maximum carbon atoms in coke (Cmax) from 898 (Additive-free system) to 670, compared to methanol's reduction to 745. CH3OH shortens the carbon chain length by attacking the unsaturated carbon chain through the formation of stabilizing C-O products by-OH, while NH3 reduces the number of unsaturated small molecules through the formation of C-N products, and the inhibitory mechanism of the carbon chain lengthening process by the C-N species in the growth process of PAH has been revealed for the first time. This study systematically elucidates the different mechanisms of methanol and ammonia blending to inhibit coking of RP-3 fuel from the atomic scale, which provides an important theoretical basis for the optimization of aviation fuel formulations and the design of coking prevention of engine thermal management systems for low-carbon fuels.

ABSTRACT Low‐temperature ammonia‐selective catalytic reduction (NH 3 ‐SCR) over MnO 2 is attractive for nitrogen oxides (NO x ) abatement yet is intrinsically penalized by nitrous oxide (N 2 O) formation, a potent greenhouse byproduct. Here, we show that oxygen‐site nonmetal substitution in β ‐MnO 2 can simultaneously suppress N 2 O and accelerate NH 3 ‐selective SCR, enabled by a feasibility‐to‐mechanism computational workflow. Screening by structural compatibility, orbital hybridization, thermochemical and kinetic stability identifies viable dopants, among which F and S most effectively rewire reaction branching. Kinetics estimated by the density functional theory calculations reveal that F and S raise the N 2 O‐forming rate‐determining barrier from 0.80 eV to 0.93/0.92 eV, while lowering the N 2 ‐forming barrier from 0.48 eV to 0.40/0.42 eV. At 200°C, F‐ and S‐doped β ‐MnO 2 increase TOF by a factor of 8.40 and 4.24, respectively, and enhance kinetic N 2 selectivity by a factor of 1.66 and 1.38, respectively. We identify Mn( d )–nonmetal( p ) band center alignment as a mechanistic descriptor that points to a volcano‐like trend for the energy barriers of N 2 O and N 2 , supported by Bader charge, COHP/ICOHP, and ELF analyses. These results serve as a theoretical design reference for tuning the activity–selectivity trade‐off in oxygen‐site–modified oxide SCR catalysts.

Wear-induced degradation remains a persistent challenge in heavy machinery industries. In this work, we developed a novel self-shielded flux-cored wire for fabricating Fe-Cr-C-V-xTi hardfacing alloys via open-arc welding, and more importantly, we achieved the first direct in situ observation of the heterogeneous nucleation of primary M7C3 carbides by high-temperature confocal microscopy. This breakthrough enables real-time visualization of carbide nucleation, which has been previously inferred only from post-solidification microstructural analyses. The results demonstrate that Ti addition promotes the formation of (Ti,V)(C,N) carbonitrides, which precipitate prior to M7C3 carbides and serve as effective nucleation substrates. Microscopic characterization revealed clear epitaxial relationships between (Ti,V)(C,N) particles and M7C3 carbides. Increasing Ti content (0-0.46 wt%) progressively refined primary carbides, while the alloy with 0.46 wt% Ti exhibited optimal wear resistance, reducing mass loss by 25 % compared to the Ti-free alloy. Complementary first-principles calculations further confirmed that the interfacial energy between (Ti,V)(C,N) and Fe3Cr4C3 is significantly lower than the solid-liquid interfacial energy, thermodynamically validating heterogeneous nucleation as the dominant pathway. This work not only provides the first dynamic evidence for the heterogeneous nucleation mechanism of M7C3 carbides, but also establishes a strategy to tailor microstructures and enhance wear resistance in Fe-based hardfacing alloys.

Efficient thermal transport network based on vertically aligned carbon nanotubes (VACNTs) require the deposition of a high-quality metal coating. However, due to the chemical inertness of the graphene lattice, conventional metal deposition methods often fail to ensure effective thermal conduction through every CNT within VACNTs array. To address this challenge, we propose a reactive impregnation wetting strategy for creating heat transfer channels between VACNTs and metals. By introducing a reactive element (i.e., Ti), we promote the impregnation wetting of a high-thermal-conductivity liquid alloy into the array, simultaneously ensuring robust bonding between the VACNTs and smooth copper foils. The resulting Cu-VACNTs-Cu sandwich structure exhibits remarkable thermal transport properties, achieving through-plane of 18.8 W & sdot;m-1 & sdot;K-1 which represent 2.4-fold improvements compared to pristine VACNTs. Moreover, the contact thermal resistance of our structure is approximately one-third that of pristine VACNTs in direct dry contact with the device. These findings not only optimize the intrinsic heat transfer channels of VACNTs but also introduce liquid metal reactive impregnation wetting strategy as an innovative approach for designing advanced thermal transport networks, fully leveraging the thermal management advantages of VACNTs.

Zr alloys are widely used as cladding materials in light-water reactors because of their low neutron absorption and excellent corrosion resistance. However, achieving high-quality diffusion bonding of Zr alloys at conventional high temperatures is challenging, where grain coarsening and formation of interfacial secondary-phase particles (SPPs) degrade joint performance and may compromise the dimensional accuracy of precision components. This study develops a low-temperature, high-strength diffusion-bonding technique for Zr-4 alloy via surface nanocrystallization, and elucidates the associated microstructural evolution and strengthening mechanisms. A gradient nanostructure (GNS) with a thickness of approximately 70 mu m was fabricated on the Zr-4 alloy surface via ultrasonic impact treatment (UIT). The GNS comprised nanograins, nanolamellae, and deformed grains, with high densities of grain boundaries, dislocations, and twins. This surface nanostructure was designed to enhance atomic diffusion, reduce bonding temperature, and improve joint properties. Diffusion-bonding experiments were performed for 30 min at temperatures ranging from 740 degrees C to 800 degrees C under a pressure of 10 MPa. The results revealed that the surface nanograins significantly accelerated interfacial void closure and suppressed SPPs overgrowth and aggregation, resulting in a more dispersed distribution of SPPs along the bonding interface. Abnormal grain growth appeared at 15-100 mu m from the bonded interface, with the largest grains reaching up to 7.2 times the size of the matrix grains. This abnormal grain growth is attributed to the uneven distribution of strain energy within the GNS, which enables some grains with energy, orientation, or size advantages to grow preferentially by continuously consuming surrounding finer grains. Fracture behavior analysis revealed that cracks initiated neither at the bonded interface nor within the abnormally large grains, but in the Zr matrix region approximately 130 mu m from the interface. These grains exhibited numerous deformation twins and acted as crack propagation barriers by coordinating deformation with the surrounding finer grains. Despite their lower yield strength, the abnormally large grains positively contributed to joint strength through a strengthening mechanism induced by hetero-deformation. The shear strength of the Zr/Zr and GNS-Zr/GNS-Zr joints improved as the bonding temperature increased. The GNS-Zr/GNS-Zr joint achieved the highest shear strength of 376.9 MPa at 800 degrees C. Under the same bonding conditions, GNS-Zr/GNS-Zr joints exhibited 1.2-1.6 times higher shear strength than the Zr/Zr joints, with greater improvements at lower temperatures.

Porous organic cages (POCs), owing to their high specific surface area and tunable chemical properties, hold significant potential in gas separation membranes. However, the construction of POC membranes featuring highly interconnected angstrom-scale channels remains a formidable challenge. In this work, an innovative amine functionalization strategy was employed to successfully synthesize a water-soluble, amine-rich functionalized POC. Crucially, pendant ethylamine side chains on the cage framework enabled the weaving of discrete POC units into ultrathin polycage membranes via an amidation crosslinking reaction with terephthaloyl chloride, thereby constructing highly interconnected angstrom-scale amine-rich channels. The abundant amine groups within these channels display strong preferential adsorption toward CO2, functioning as highways for CO2 molecular shuttling. The polycage membrane exhibited an exceptional CO2 permeance of 920 GPU and CO2/N2 selectivity of 42.4, along with excellent long-term stability, significantly surpassing most previously reported POC membranes. Furthermore, applying this polycage membrane to a two-stage membrane process for separating CO2/N2 mixed gas in simulated flue gas yielded a CO2 purity as high as 99.5%. This work not only innovatively proposes ultrathin polycage membranes featuring tailored pores and their molecular shuttling mechanism, but also establishes a novel pathway for the seamless assembly of discrete porous molecular units into functional membranes.

Variant selection exerts a pronounced influence on the microstructural evolution and resultant mechanical performance of near-alpha titanium alloys, particularly in additively manufactured specimens, owing to their prevalent high-strain state. To explore variant selection and microstructure in laser powder bed fusion (LPBF) thin-walled Ti-6.5Al-2Zr-1Mo-1V (TA15) titanium alloy structures before and after thermomechanical processing (TMP), the precipitation of alpha variants was investigated systematically. Due to the self-accommodation of transformation shape strain, the LPBF sample exhibited a dominance of Type IV (63.26 degrees/[10 5 5 3]) intervariant boundaries and resultant parallel arrangements of alpha ' variants. During heat treatment, prior-beta grains with habit planes nearly parallel to the polished surface developed a transformation texture, which was ascribed to the dominant Type IV boundaries inherited from the as-built state. In contrast, under an external stress of 10 MPa, homogeneous texture components were formed in the TMP sample, which contributed to an optimal strength-ductility balance, with an ultimate tensile strength of 1083 MPa and an elongation of 13.3%. During TMP, variant selection exhibited a biphasic response to increasing stress: initial suppression was followed by pronounced enhancement. A high applied stress (30 MPa) promoted the preferential growth of favorably oriented variants, resulting in a pronounced transformation texture within prior-beta grains. These findings on variant selection and microstructural evolution during 3D printing and TMP are beneficial for further application of LPBF thin-walled titanium structures in the field.

Direct brazing was employed to fabricate a “Cu circuit layer–Si₃N₄ ceramic–Cu heat sink” structure for power electronic devices, enabling a shortened heat dissipation path and enhanced thermal management. Structural components (60mm × 60mm and 30mm × 30mm) were brazed at 780 °C for 20min to simulate finless and finned heat sinks. The effects of composite brazing filler metal and copper underlayer stiffness on warpage and thermal resistance were systematically evaluated. Results show that composite fillers effectively suppressed warpage, reducing deformation in a 60 × 60mm²-finned component from 0.95% to 0.73%, with a measured thermal resistance of 0.1936 K/W. After surface soldering of the IGBT, the total thermal resistance from junction to ambient decreased by 10.2% compared with conventional structures. This study demonstrates a practical route to improve heat dissipation and optimize the thermal design of high-power modules, providing an industry-ready thermal management solution for high-power-density SiC/GaN devices.

Alloy 617 is widely utilized in critical high-temperature components across advanced ultra-supercritical power plants and very high-temperature reactors. Post-weld heat treatment (PWHT) is known to suppress stress-relaxation cracking in alloy 617, but its specific impact on the mechanical properties of the heat-affected zone (HAZ) has not been investigated. In this study, a Gleeble thermal simulator was utilized to reproduce the simulated HAZ thermal cycles at 750, 1050 and 1320 °C, to systematically investigate the influence of PWHT on the microstructure and mechanical properties of these regions. It was revealed that PWHT promoted the formation of continuous M23C6 carbide networks along grain boundaries, increasing the average carbide size from 0.31-0.45 μm to 0.55-0.69 μm and the area fraction from 1.52-2.44

To address the limitations of high‐temperature diffusion bonding in zirconium alloys, the effect of controlled hydrogenation is investigated on bonding behavior, microstructure evolution, and joint performance. Zirconium alloy with 0, 200, and 2000 ppm hydrogen are prepared for diffusion bonding at 700–800 °C under 15 MPa for 30–120 min. At 200 ppm hydrogen, hydrides decomposed during bonding and reprecipitated along the interface upon cooling, eliminating interfacial voids and preserving finely dispersed second‐phase particles around equiaxed α ‐Zr grains with minimal coarsening. At 2000 ppm hydrogen, incomplete hydride decomposition resulted in residual hydrides, while β ‐Zr at grain boundaries softened the interfacial grains without extensive recrystallization, maintaining grain sizes below 7 μm. Hydrogenation lowered the required bonding temperature, where joints bonded at 700 °C with 200 ppm hydrogen achieved shear strengths of 220 MPa, comparable to un‐hydrogenated joints bonded at 750 °C. Similarly, 2000 ppm hydrogen enabled comparable strength at 720 °C to that of un‐hydrogenated joints bonded at 780 °C. Molecular dynamics simulations confirmed that hydrogen‐induced hydrogen‐vacancy clusters enhanced atomic diffusion, while finite‐element modeling demonstrated that hydrogen‐induced softening lowered local stress concentrations and promoted void closure during bonding. These multiscale insights clarify the mechanisms where hydrogen enhances diffusion bonding efficiency and joint properties in zirconium alloys.

Formaldehyde-based wood adhesives raise environmental and health concerns, creating demand for sustainable mineral-based alternatives. However, magnesium oxychloride cement (MOC) adhesives still suffer from poor water resistance and weak interfacial bonding. Here, we introduced three natural polysaccharide-derived sodium carboxylates with distinct chain topologies, namely sodium alginate (SA), sodium carboxymethyl cellulose (CMC), and sodium carboxymethyl starch (CMS), into the MOC matrix. Their different architectures altered the spatial distribution and accessibility of carboxylate groups, leading to distinct coordination and confinement effects. These differences influenced crystal growth, microstructure evolution, and interfacial interactions, resulting in concentration-dependent performance. Among the modifiers, 0.5 wt% SA delivered the best overall performance, with a 28 d compressive strength of 97.58 MPa and a water resistance coefficient of 0.74. The corresponding eucalyptus veneer adhesive achieved dry and wet bonding strengths of 1.33 and 0.79 MPa, respectively. The improvement arose from coordinated regulation of hydration products, pore structure, and the wood–MOC interface. This study establishes a topology-guided strategy for developing high-performance, formaldehyde-free mineral-based wood adhesives.

Selective d z 2 –p z orbital coupling and d–d hybridization inhibit N 2 O formation in 3d transition metal-doped MnO 2 , showing a volcano relationship, guiding catalyst development and enhancing selectivity via electronic structure control.

To develop heterostructures of high-entropy carbides (HECs) for extreme acidic corrosive, a Nb-based interlayer is constructed in the (HfZrTiTaNb)C HEC joint through diffusion-induced in-situ alloying of Nb with Ni. Corrosion behavior of the diffusion-bonded structure is investigated after immersion for up to 240 h in an oxidation-enhanced 3.5 M nitric acid at 25–70 °C. The Nb passivation in the Nb-based interlayer ensure consistent corrosion resistance. The Nb2Ni/HEC bonded interface remain intact throughout, at which the microgalvanic couple cause preferential erosion of the HEC. The HEC corrosion mechanism involving the synergistic participation of multiple atoms is revealed. The Hf, Zr, and Ti in the HEC tend to dissolve into nitric acid, while the Nb and Ta primarily form a dense layer, which is confirmed to be an amorphous oxide containing the evolution of multiple components along its thickness direction. The amorphous oxide layer provide effective protection for the HEC, despite the notches triggered by the oxygen-induced volume expansion. When HEC grain boundaries are preferentially attacked, crystal defects propagate, rather than the grain boundaries failing directly. The stable high-entropy lattice confer corrosion resistance advantages to the HEC. These results will provide insights for the design of HEC bonding structures targeting extreme environments.