Radioactive iodine (I2) poses a serious threat to human health and has become a central challenge in global marine nuclear waste management. This study reports an AgCl-UiO-66@MAO hierarchically dispersed coating constructed via a loading-dispersion strategy for the efficient capture of radioactive I2 in marine environments. This strategy employs high-surface-area UiO-66 nanocrystals as carriers to achieve surface loading of AgCl nanoparticles and utilizes the porous micro-arc oxidation (MAO) layer on Ti alloy surfaces to disperse the active components, thereby effectively suppressing the aggregation of AgCl nanoparticles and maximizing the exposure of active sites. The experimental and DFT calculation results demonstrated that the maximum saturation adsorption capacity of I2 for the AgCl2.41-UiO-66@MAO coating reached 1228.9 mg·g⁻¹ and the diffusion coefficient was 4.61 × 10–3 m2·s–1, significantly outperforming the vast majority of analogous adsorbents reported to date. Mechanistic studies revealed that this process is dominated synergistically by electrostatic interactions between Zr-oxo clusters and I2, and by strong chemisorption between I2 and AgCl nanoparticles. The introduction and effective dispersion of AgCl nanoparticles constructs additional chemisorption sites, resulting in a 41.33% enhancement in total saturation adsorption capacity compared to the AgCl-free coating. Furthermore, the coating exhibits a corrosion current density of 2.61 × 10⁻11 A/cm2 in a simulated seawater environment, representing a three-order-of-magnitude reduction compared to the MAO-Ti substrate and demonstrating superior corrosion resistance. The coating maintains structural stability across a pH range of 3–7 and under competitive ion coexistence conditions, retaining 97.67% I2 removal efficiency and 99.3% desorption efficiency after 10 regeneration cycles. This study provides a high-capacity, long-lifespan, and scalable technological paradigm for efficient remediation of radioactive I2 in seawater.

The inherent crystallographic anisotropy of hexagonal close-packed (HCP) structures limits uniform plastic deformation in near-alpha titanium alloys. Investigating TA18 alloy under rolling deformation, enhanced strength and plasticity with increasing reduction correlate with intensified slip activity at high-angle grain boundaries (HAGBs). This promoted atypical dislocation transmission across HAGBs, improving intergranular strain compatibility. Molecular dynamics simulations reveal an atomic-scale mechanism: stress concentrations at HAGBs nucleate new dislocations, with grain boundary nodes acting as potent emission sites. This multi-point emission critically facilitates strain accommodation, providing a key pathway to mitigate HCP plastic deformation constraints.

Wear-resistant coatings for variable load conditions remain a challenge. To address this, we investigate MoS2/ GO/TiO2 coatings with varying graphene oxide (GO) content, combining multi-step nonlinear load wear testing with Miner's cumulative damage criterion. Compared with traditional plasma electrolytic oxidation coating, the coating containing 5 g/L GO exhibits 4.66 times longer mean useful life, a 27.18 % increase in cumulative damage resistance, and maintains a stable, extremely low coefficient of friction. This significant improvement is attributed to a double incoherent interface structure within the coating, which reduces local stress concentration by promoting dislocation dipole formation, thereby enhancing durability under variable load wear.

The architecture of coatings critically determines the wear resistance of titanium alloys. However, research on damage evolution mechanisms under variable loading conditions remains limited for titanium alloy coatings. In this study, the grain size gradient (GSG) coating was fabricated using plasma electrolytic oxidation, and its tribological behavior was systematically investigated under constant, step, and periodic step loading conditions. The results indicate that the GSG coating significantly enhances tribological performance by facilitating strain delocalization and enabling dynamic reorganization of the tribofilm. Under constant loading, increased load intensifies strain localization, leading to progressive tribofilm failure and oxidative wear. In contrast, periodic step loading promotes cyclic recovery, allows for tribofilm reorganization and thereby mitigate damage. Compared to step loading, the periodic step loading regime yields a lower, more stable coefficient of friction and reduced wear loss. This study offers valuable insights for designing coatings on titanium alloys suited to complex loading environments.

To enhance the tribological properties of titanium alloys, three composite coatings were fabricated on TC4 alloy via a hybrid process combining pack cementation (PC) and plasma electrolytic oxidation (PEO). Boronizing, carburizing, and borocarburizing pretreatments were systematically compared to investigate their effects on the phase composition, microstructure, mechanical properties, and tribological behavior of the coatings, and to clarify the coating formation and anti-wear mechanisms. The borocarburized PEO coating (B-C/PEO) featured a synergistic system of TiB/TiC hard phases and an H3BO3 lubricating phase, along with a denser microstructure and lower surface roughness. The results show that the B-C/PEO coating exhibits an average friction coefficient of approximately 0.18. Its wear rate is as low as 1.573 & times; 10-4 mm3 center dot N- 1 center dot m- 1, which is 45.13% and 58.23% lower than those of the other two PEO coatings respectively. This is mainly attributed to the hard phases endowing the coating with a high microhardness of approximately 627 HV0.2 to resist plastic deformation. The optimized structural and surface features enhance its load-bearing capacity while the laminated structure of H3BO3 disperses frictional stress and forms local self-lubricating regions. Its wear mechanism is mild abrasive wear, which endows it with excellent wear resistance compared with its counterparts.

Achieving simultaneous high strength and ductility in titanium (Ti) alloys remains a challenge due to the intrinsic trade-off between these properties. This work reports the sequentially-activated multiple deformation mechanisms in a heterogeneous TA18 alloy, including hetero-deformation induced (HDI) hardening, kink band-induced plasticity (KBIP), and twinning-induced plasticity (TWIP). These mechanisms play a pivotal role in regulating strain partitioning and facilitating multi-scale synergistic deformation. Kink bands (KBs) serve a dual function: providing additional strain hardening by impeding dislocation motion, while simultaneously accommodating plastic flow through morphological evolution. Critically, the interaction between KBs and twins activates additional slip modes, effectively mitigating strain localization and thereby suppressing microcrack nucleation and propagation. Furthermore, atomic-scale analysis elucidates a novel plasticity mechanism: the dynamic transformation of KBs into { 101 2 } extension twins driven by the accumulation of basal ( a ) dislocations and lattice rotation. The synergistic interplay between KBs and twins effectively accommodates severe local strain incompatibility, thereby delaying the onset of necking. These findings provide valuable insights into the plasticity mechanisms of Ti alloys and offer valuable guidelines for the microstructural design of advanced structural materials. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

Nanocrystalline ceramic coatings exhibit high hardness but limited toughness due to pronounced strain localization, which remains a key limitation for their protective applications. Most toughening strategies have focused on either reducing strain localization or facilitating strain transfer during deformation, whereas their concurrent realization remains challenging. In this study, inspired by wood cell walls, a nanocrystalline-amorphous network structure ceramic coating (NSCC) was prepared by introducing an amorphous interphase (AIP) into the nanocomposite coating on the surface of the titanium alloy by plasma electrolytic boriding and plasma electrolytic oxidation (PEO). The findings revealed that the continuous AIP is formed in-situ within the nanocrystalline matrix, providing accommodation for dislocation-mediated plasticity. The NSCC achieves the hardness of 9.24 GPa and fracture toughness of 5.92 MPa·m1/2, corresponding to increases of approximately 81% and 70%, respectively, relative to nanocrystalline coatings by conventional PEO. Through AIP, the coating mitigating strain concentration and facilitates strain transfer, and the resulting defect structures, which are capable of co-deformation, serve as the primary mechanism underlying the improved performance of NSCC. The coating design and preparation strategy provides an effective and efficient route to high-strength, high-toughness ceramic coatings.

Overcoming the intrinsic strength-ductility trade-off remains a central challenge in developing advanced titanium (Ti) alloys, as conventional strengthening strategies invariably sacrifice ductility. Here, we propose a dislocation engineering strategy that deliberately constructs ordered dislocation networks in the TA18 alloy, achieving exceptional strength-ductility synergy. These ordered geometric architectures are robustly stabilized by sessile jogs originating from specific crystallographic interactions between and dislocations. During early deformation, the networks subdivide grains into fine deformable units, providing massive initial strain hardening by impeding mobile dislocations via the dislocation jog dragging effect. With progressive strain, inhomogeneous local stresses drive the sweeping out of jogs, dynamically transforming the static networks into glissile dislocation arrays and dense dislocation walls. This critical structural evolution triggers a fundamental transition to a “transport-dominated” plasticity regime, activating potent hetero-deformation-induced strengthening and indirect slip transfer. These findings establish a scalable paradigm for designing high-performance Ti alloys via dislocation architecture control.

Plasma electrolytic oxidation coatings are widely studied under constant-speed conditions, yet real-world applications involve variable speed operation. This study investigates the tribological behavior of ZrB2/TiO2 composite coatings under constant speeds (50-200 rpm) and four variable speed protocols. Control experiments demonstrate that speed-dependent mechanical processes dominate friction variation (similar to 85%), while thermal effects are secondary (similar to 15%). A pronounced irreversible surface memory effect was identified: friction remained elevated by 60-90% following high-speed exposure due to permanent surface modifications. Critical speed change rate thresholds defined three operational zones: safe (<2 rpm/cycle), caution (2-10 rpm/cycle), and critical (>10 rpm/cycle). Triangle wave patterns with 25-35 rpm amplitude achieved 41-44% fatigue life improvements through stress redistribution. These findings establish that maximum historical speed-rather than instantaneous parameters-governs tribological performance, providing quantitative design safety factors (1.5-2.5 & times;) for variable speed applications.

Although micro-arc oxidation (MAO) coatings improve the mechanical properties of titanium alloys, their porous structural defects tend to act as pathways for corrosive agents and as adhesion sites for contaminants. In this study, a superhydrophobic coating was developed on TC-4 titanium alloy by combining in-situ hydrothermal synthesis of ZIF-8 with POTS surface modification, thereby forming a rough surface with low surface energy. The POTS/ZIF-8@MAO composite coating exhibits strong adhesion to the substrate through both physical and chemical bonding. Consequently, it demonstrates excellent chemical and thermal stability, maintaining a water contact angle (WCA) of 156.53 degrees +2.47 degrees and a sliding angle (SA) of 6.32 degrees +1.16 degrees even under extreme conditions. Due to its low water adhesion, the coating demonstrates significant self-cleaning ability against both solid and liquid contaminants. Electrochemical analysis reveals that it improves corrosion inhibition by up to 99% compared to pristine MAO-treated titanium alloy, providing an effective protective barrier for the substrate. This work proposes a promising strategy that may potentially expand the application scope of titanium alloys.

This work investigates the configurational evolution of basal-pyramidal (B-P) dislocation locks in TA18 alloy and their influence on deformation incompatibility. We reveal that complex dislocation reactions lead to significant intergranular deformation heterogeneity, even under conditions of low slip transmission resistance. Specifically, basal (a) dislocations interact with pyramidal (c + a) dislocations to form sessile B-P locks, which significantly impede dislocation motion and induce localized stress concentrations. Furthermore, we characterize the metastable nature of pyramidal (c + a) dislocation within the B-P lock and elucidate its dissociation into basal (a) and prismatic (c) dislocations. This dissociation is identified as a thermodynamically driven process of dislocation core reconstruction, ultimately facilitating plastic flow. The physical origin of dislocation dissociation lies in the transformation of high-energy dislocation cores into low-energy configurations on alternative slip planes. These findings provide valuable insights into the multi-scale coupled mechanisms governing plastic deformation in titanium alloys.

Stellite 6 alloy coatings reinforced by micron-nano dual-scale WC ceramic particles were fabricated on the surface of IN718 alloy using the laser cladding technique. The microstructure of the composite coating comprises dendritic gamma-Co solid solution and various carbides (i.e., M23C6, M7C3, and W2C). The micron-sized WC reacts with the matrix and forms a discretely distributed eutectic structure. In contrast, the introduction of nano-sized WC results in a networked eutectic carbides, grain refinement, and a significant increase in the overall coating hardness. The addition of dual-scale WC enhances the wear resistance and prevents porosity defects in the composite coating. Compared to coatings reinforced solely with micron-sized or nano-sized WC, the dual-scale WC reinforced coating exhibits reductions in wear rate of 9.3% and 19.3% at room temperature, and 12.6% and 39.8% at 500 degrees C, respectively. This enhancement originates from two mechanisms: the nano-sized WC addition strengthens the gamma-Co matrix by eutectic carbide network and grain refinement, while the unmelted micron-sized WC particles provide the load-bearing effect, thereby reducing contact area and alleviating stress concentration.

As a prototypical structural metallic material, AZ91D magnesium alloy is widely used in aerospace and automotive applications due to its low density and high specific strength, but its poor surface durability remains a critical limitation. To enhance service reliability, ceramic coatings have been developed as protective barriers. In ZrO2-doped plasma electrolytic oxidation (PEO) coatings, a key challenge is the inefficient stabilization of yttria-stabilized tetragonal zirconia (YSTZ), caused by severely hindered Y3+ interfacial transport under non-equilibrium discharge conditions. The rapid and competitive formation of Y2O3 and ZrO2 generates structurally disordered or weakly coherent interfaces, increasing the diffusion barrier for Y3+ migration and suppressing t-ZrO2 stabilization, thereby degrading fracture toughness. To address this issue, a reaction-sequence-regulated PEO strategy combined with machine learning was developed to construct a low-interfacial-energy Y2O3/t-ZrO2 coherent interface, converting it from a diffusion barrier into a transport pathway. First-principles calculations reveal a reduced Y3+ migration barrier of 0.566 eV (9.87% lower than conventional PEO). Optimization shows that interface continuity and strain homogeneity are highly sensitive to Y concentration, where both deficiency and excess suppress diffusion. The optimized coating achieves 74% YSTZ with significantly improved fracture toughness while maintaining high hardness. This work establishes a mechanistic link among reaction control, coherent interfaces, strain-regulated diffusion, and macroscopic performance, providing a general strategy for toughened ceramic coatings.

Research on high-performance Ti alloys incorporating oxygen (O) has remained a laboratory procedure and is hindered by the unresolved issue of O segregation-driven failure. Here, we demonstrate that O can tailor a nanoscale local range order O (LRO-O) structure between the oxide and random interstitials in Ti alloy. We introduce 0.36 wt% O into metastable Ti-5Al-5Mo-5V-3Cr alloy using a short-term powder metallurgy approach to produces large-scale materials. The LRO-O structure in designed alloy prevents crack initiation by promoting the active nucleation of -type dislocations and altering the slip modes during tensile and fatigue failure. The alloy has high strength (1.7 GPa), elongation (7.9%), and fatigue strength (1058.3 MPa), which outperforms many high-strength, high-O Ti alloys. Our findings provide a scalable, practical route to superior mechanical properties for Ti alloys without costly alloying elements.

This work designs the core-shell structure in Ni-W coating with nanocrystalline wrapped by amorphous, which can enhance wear resistance. The Ni4W crystalline is first formed during co-deposition, and tungsten atoms are preferentially segregated to the crystalline interface, resulting in lattice distortion. It leads to the conversion of the crystalline to amorphous at the boundary, thus forming the core-shell structure with an alternating distribution of crystalline and amorphous. The core-shell structure can relieve stress concentration and inhibit the emergence of microcracks through coordinated deformation, which improved strength and enhanced wear resistance in coating. As a result, the Coating 30 has the best corrosion and wear resistance with a corrosion potential of -0.4394 V, an average coefficient of friction of 0.51. This work is expected to provide an important technical reference for the preparation of high-performance Ni-W coatings.

A MoS2 concentration gradient coating of an osteoarticular-like structure with efficient strain transfer efficiency was prepared on titanium alloy via multiple plasma electrolytic oxidation. This structure facilitates efficient strain transfer by dissipating compressive and shear strains via dislocation annihilation and MoS2 interlayer sliding, thereby preserving a strain gradient. Leveraging this mechanism, the coefficient of friction was reduced by 50.2% compared to graphene coatings, while the frictional stabilization time was extended by 160% about Single MoS2/TiO2. This study elucidates the dislocation behavior and the mechanisms of strain transfer during friction within this structure.

The inherent porous structure of Micro-arc oxidation (MAO) coatings may facilitate penetration of corrosive ions into the substrate, thereby compromising its corrosion resistance. In this work, the metal-organic framework (MOF) ZIF-8 was employed to seal the micropores in the MAO coating of titanium alloy (MAO-Ti) through a secondary growth method involved initially physically pre-loading crystal seeds into the micropores, followed by solvent thermal synthesis. Consequently, an excellent cohesive pore-sealing coating known as ZIF-8@MAO was successfully developed. The anchoring effect between ZIF-8 in the micropores and the substrate forms a solid blocking layer, which can effectively avoid the issue of traditional sealing layers detaching easily. Additionally, the arranged ZIF-8 crystals on the surface of MAO-Ti imparts excellent hydrophobicity and high stability to the alloy, evidenced by contact angle tests conducted under various solution environments, where the water contact angles (WCAs) exceeded 140 degrees. Moreover, ZIF-8 microcrystals act as effective sealants for the micropores of MAO- Ti, effectively safeguarding the internal titanium alloy matrix against chloride ion infiltration and ensuring longterm corrosion resistance. Electrochemical tests assessing the corrosion resistance of the coatings revealed a significant improvement in the corrosion resistance of the ZIF-8@MAO pore-sealing coating compared to the primary MAO-Ti coating. The charge transfer resistance (Rct) increased from 2.05 x 104 Omega/cm2 to 1.287 x 109 Omega/cm2, while the current density (Icorr) declined from 2.03 x 10- 8 A/cm2 to 2.65 x 10-13 A/cm2.

In this study, CrFeNiTixAl1-x (x=0.3, 0.7 in mole ratio) high-entropy alloy coatings (referred to as Ti0.3Al0.7, Ti0.7Al0.3 alloy coating, respectively) were prepared on AlSI1045 steel using the laser cladding (LC) method by adjusting the Al and Ti element contents. The phase constitutions, microstructures, mechanical properties, and corrosion resistance of the prepared coatings were comprehensively investigated and compared. Both Ti0.3Al0.7 and Ti0.7Al0.3 coatings exhibited rich Fe-Cr disordered BCC phase (A2) and NiAl ordered BCC phase (B2). The L21 phase in the Ti0.7Al0.3 coating accounted for as much as 47.7% when the Ti content was 0.7. The elevated Ti content significantly refined the internal structure of the coating, reducing the average grain size from 7.495 mu m to 2.281 mu m. With the combined effect of grain refinement and obstruction of dislocation motion by large angle grain boundaries, the microhardness of the Ti0.7Al0.3 alloy coatings increased from 685.12 HV0.2 to 867.20 HV0.2 compared to Ti0.3Al0.7. The precipitation strengthening effect of the noncoherent hard L21 phase, along with the protective role of the TiO2 oxide film, resulted in the lowest friction coefficient of 0.171 for Ti0.7Al0.3. Ti0.7Al0.3 exhibits the dominant wear mechanisms of abrasive and oxidative wear. Meanwhile, these coatings also exhibited excellent resistance to Cl- corrosion, with corrosion potentials shifted to -0.52 V and -0.46 V for Ti0.3Al0.7 and Ti0.7Al0.3, and corrosion current densities decreased to 1.26 x 10-6 A/cm2 and 4.35 x 10- 7A/cm2, respectively. These findings suggest that the replacement of equimolar Al with equimolar Ti in the CrFeNiTiAl high-entropy alloy compositions is a meaningful phenomenon that offers new perspectives for the design of novel high-performance HEAs.

A novel near-alpha titanium alloy designed for cryogenic applications was fabricated via laser direct energy deposition process. The microstructures and cryogenic mechanical properties of the alloy before and after heat treatment were analyzed. Both as-deposited and annealed alloys demonstrate remarkable strength-ductility synergy. Notably, the elongation of annealed alloy (similar to 17.5 %) is about 84.2 % higher than as-deposited alloy, while maintaining high ultimate tensile strength (similar to 1174 MPa). To comprehensively examine the impact of microstructure on cryogenic deformation, in-situ cryogenic TEM strain testing and other analytical techniques were employed, which offer new insights into the multiscale deformation mechanisms at cryogenic temperature. Larger alpha phase facilitates twin nucleation and effectively accommodates the strain gradient resulting from inhomogeneous deformation. Multiple twins promote non-basal dislocation slip and introduce additional heterogeneous interfaces, enhancing both twinning-induced plasticity and dynamic Hall-Petch effect. As flow stress increases, < c + a > dislocations near twins dissociate into < c > and < a > dislocations, contributing to dislocation strengthening. The notable enlargement of grain size in annealed alloys facilitates more active dislocation behavior driven by extensive twinning, promoting sustained strain hardening. These findings not only elucidate the cryogenic deformation mechanism of near-alpha titanium alloy but also offer promising avenues for developing high-performance titanium alloys by additive manufacturing.