High-temperature creep limits the use of die-cast magnesium alloys in load-bearing components. The long-term deformation of Mg–Al-based die castings, however, remains insufficiently understood. We report a heat-treatment-free die-cast Mg–RE–Al alloy, JDM1C, with asymptotic creep behavior. During 100 h creep tests, the accumulated strain approached a finite saturation value. The creep rate decreased continuously toward a near-zero steady-state regime. This response departs from the unbounded strain accumulation predicted by the Norton–Bailey model. Microstructural evidence links the behavior to competitive phase formation during solidification. RE and Ca preferentially react with Al to form thermally stable Al–RE and Al–Ca intermetallics. This suppresses the creep-susceptible β-Mg₁₇Al₁₂ phase. The resulting discontinuous grain-boundary reinforcement network restricts grain-boundary sliding, inhibits connected damage, and stabilizes the microstructure during prolonged exposure. From these observations, an asymptotic creep constitutive model was developed. The model incorporates asymptotic creep strain, a critical transition time, and exponential temperature dependence. It reproduces the fitted creep response and predicts displacement in a component-level test. The results link creep stabilization with phase selection and grain-boundary architecture. The model provides a mechanistic and constitutive basis for designing lightweight magnesium alloys with improved dimensional stability.

The inflammatory pathological microenvironment of osteoarthritis (OA) degrades the cell state and function of stem cell-derived grafts and presents a major obstacle to developing effective cell therapies. Here, we show that the viability and hyaline cartilage phenotype of bone marrow-derived mesenchymal stem cell (BMSC)-derived chondrocyte microspheroids (CMSs) can be efficiently preserved during spheroidization with persistent H2 supply and in an OA microenvironment. We therefore developed TiSi2 nanosheets (TSN) that hydrolytically generate a sustained (> 2 months) high dose of H2 and construct a H2-releasing hydrogel transplant (TSN/CMS-Gel) by encapsulating TSN and CMSs within a photo-crosslinking hydrogel (Gel). Transplantation of TSN/CMS-Gel achieves a strong survival of chondrocytes in a rodent OA model and promotes the rapid and efficient repair of sheep osteoarthritic critical-size cartilage defects, as well as the reversal of osteoarthritic progression within 6 months. The proposed strategy of locally sustaining H2-mediated preservation of transplanted chondrocytes in the pathological microenvironment opens new opportunities to enhance cell transplantation outcomes.

Additive manufacturing (AM) of Mg alloy components with intricate geometries has garnered increasing interest for achieving lightweight structure and material simultaneously. However, cracking and coarse-grained microstructure remain critical challenges, severely compromising the strength and ductility of the as-built Mg alloys. Here we leverage multi-scale experimental characterizations and high-fidelity simulations of melt pool dynamics and thermal stresses to understand the crucial role of alloy composition in mitigating cold cracking, enhancing grain refinement and improving mechanical properties in AM of Mg-Gd(-Zn)-Zr alloys, aiming to establish comprehensive alloy composition design guidelines. We uncover an unusual paradox between reducing cold cracking susceptibility and refining grains when tailoring the alloy compositions. The solidification growth restriction factor (Q value) plays a pivotal role in grain refinement through the constitutional supercooling effect, with a recommended Q value exceeding 32 K. Cold cracking occurs when accumulated solidification shrinkage and thermal contraction stresses surpass the ultimate tensile strength of the material. To quantitatively evaluate this, we introduce a novel cold cracking index (CCI) that incorporates the sample size, as well as the height and width of the first crack. Mg alloys with intrinsic properties such as high ductility, high thermal conductivity, and low thermal expansion coefficient are identified as more suitable for AM process to avoid cold cracking. These guidelines are validated by successful fabrication of Mg-11Gd-2Zn-0.3Zr (wt.%, GZ112K) alloy, which turns out to be cracking-resistant, fine-grained, and strength-ductility synergistic. This work provides deeper insights into the cold cracking and grain refinement mechanisms and presents AM design guidelines for Mg alloys with improved printability, microstructure and mechanical properties.

Ultra-lightweight magnesium alloys characterized by high specific strength are highly sought after for applications in the automotive and aerospace industries. However, conventional magnesium alloys behave poor corrosion resistance when exposed to moisture, which significantly reduces their service life, thus limiting their applications and hindering effective realization of their lightweight advantages. Here, we develop a novel stainless Mg-2Sc-0.5Al alloy, which exhibits the lowest corrosion rate of 0.027 mm/year among all reported magnesium alloys and behaves insensitivity of Fe impurity content. More remarkably, the surface film of this stainless magnesium alloy possesses the ability to fully self-heal within hours of being scratched, which gives superior and long-term protection. The superior corrosion resistance of the stainless Mg-2Sc-0.5Al alloy origins from the rapid formation and stabilization of a compact amorphous surface film facilitated by the addition of Al and Sc. The stable amorphous surface film effectively and rapidly shields the magnesium matrix from the corrosive media, thereby significantly enhancing the corrosion resistance. This work offers an efficient design strategy to form the protective amorphous surface film and further inspires the development of stainless magnesium alloys across various systems.

Developing highly efficient and stable iridium (Ir)-based catalysts is crucial for advancing proton exchange membrane water electrolysis (PEMWE). Herein, we synthesized a lutetium (Lu) incorporated IrOx catalyst (Lu-IrOx) by incorporating Lu into the IrOx lattice via the Adams fusion method combined with high-temperature thermal shock, effectively disrupting its long-range ordered structure. The resulting Lu-IrOx catalyst features a hybrid amorphous/crystalline domain that enriches surface oxygen vacancies and optimizes the electronic structure of Ir sites. This structural engineering endows the catalyst with outstanding oxygen evolution reaction (OER) performance in acidic electrolyte, achieving a low overpotential of 228 mV at 10 mA/cm2 and maintaining stable operation for over 90 h at 200 mA/cm2. When assembled in a PEMWE cell, Lu-IrOx enabled sustained hydrogen production at 1 A/cm2 at only 1.72 V for over 300 h. This work provides an effective doping strategy to enhance the catalytic efficiency and durability of IrO2 for renewable energy conversion.

Molecular hydrogen (H2) shows promise for tumor treatment, whereas its therapeutic potential is seriously challenged by inadequate dosing along with unclear biological mechanisms. Herein, spurred on by the first successful report with high-pressure H2 inhalation administration, we develop a locally generated hyperbaric hydrogen platform by fabricating and leveraging crystalline β-phase magnesium hydride (MgH2) as reservoirs of superior hydrogen-releasing capacity for tumor starvation therapy. The as-synthesized particles allow crystallization-controlled, prolonged H2 generation lasting days upon reaction with water, which further achieve in-situ overpressure (> 1.8 atm) in response to the acidic tumor microenvironment (TME). We find that continuous exposure to single H2 of abundant supply can suppress energy metabolism in various types of tumor cells to inhibit proliferation and induce apoptosis. Moreover, the β-MgH2 reservoir yielding significant intratumoral H2 is demonstrated in vivo for both local and systemic administration models, of marked metabolic function disruption, and excellent antitumor efficacy without causing systemic toxicity. Mechanistically, we distinguish that locally enriched H2 plays dual roles of impairing tumor aerobic glycolysis via downregulating HIF-1α/GLUT1 axis, and eliciting mitochondrial damage associated with adenosine triphosphate (ATP) deprivation, which thereby synergistically block energy production for cancer anabolism. Collectively, our work delivers a proof of concept of "safe, local, long-acting" high-pressure hydrogen treatment modality to enable efficient cancer-selective starvation therapy.

Nanoconfinement is a promising approach to simultaneously enhance the thermodynamics, kinetics, and cycling stability of hydrogen storage materials. The introduction of supporting scaffolds usually causes a reduction in the total hydrogen storage capacity due to “dead weight.” Here, we synthesize an optimized N-doped porous carbon (rN-pC) without heavy metal as supporting scaffold to confine Mg/MgH2 nanoparticles (Mg/MgH2@rN-pC). rN-pC with 60 wt

Advancing proton exchange membrane water electrolysis (PEMWE) requires robust, low-iridium electrocatalysts tailored for the acidic oxygen evolution reaction (OER). Herein, we report the construction of IrRuCoMnNdOx high-entropy oxide (HEO) nanosheets assembled from primary nanoparticles via a modified Adams fusion method coupled with high-temperature thermal shock (HTS) technology. Benefiting from the large-radius Nd-induced local lattice distortion, synergistic electronic coupling among multivalent metallic centers, and abundant oxygen vacancies trapped by rapid thermal kinetics, the nanosheets display remarkable OER efficiency. In acidic media, it achieves 10 mA cm-2 at a mere 188 mV overpotential, delivering an exceptional Ir mass activity of 910.51 mA mgIr-1. Furthermore, the catalyst demonstrates robust stability for over 300 hours (@10 mA cm-2) with negligible degradation. This study offers a novel paradigm for constructing highly-performance catalysts for sustainable hydrogen production.

Designing supports with highly dispersed single-atom (SA) noble metals is crucial for the oxygen evolution reaction (OER). Here, we synthesize Ru SA-doped spinel NiFe2O4 porous nanowires via eutectic dealloying and annealing. The catalyst achieves a high Ru loading (7.8 wt%) with uniform atomic dispersion. It delivers an ultralow overpotential of 196 mV at 10 mA cm- 2, a Tafel slope of 36.1 mV dec- 1, and 55 h stability in alkaline medium. The enhanced performance stems from the combined 1D/3D porous structure and electronic modulation by Ru SAs. This work offers a general strategy for designing high-loading SA catalysts.

Aluminum-lithium (Al-Li) alloys are extensively employed in aerospace and space structures because of their low density, high specific stiffness, and excellent fatigue resistance. However, welding of these alloys remains challenging, since the joints typically exhibit unique microstructural features, including equiaxed grain zones (EQZ) along the fusion boundary and coarse columnar grains in the fusion zone, which degrade mechanical performance and increase susceptibility to cracking. This review provides an overview of the generational evolution of Al-Li alloys and their associated weldability, highlights the advantages and limitations of major welding processes, such as laser, arc, and hybrid techniques, and systematically examines the formation mechanisms of EQZ, columnar grains, and equiaxed grain bands. Various strategies for microstructural control are compared, including filler design, pulsed current, and external-field-assisted welding. Special attention is given to grain refinement achieved through heterogeneous nucleation, dendrite fragmentation, and columnar-to-equiaxed transition. Finally, prospects for advanced microstructural control strategies are discussed, with the goal of achieving high-quality welds for next-generation lightweight structural applications.

Molecular hydrogen (H2) shows promise for tumor treatment, whereas its therapeutic potential is seriously challenged by inadequate dosing along with unclear biological mechanisms. Herein, spurred on by the first successful report with high-pressure H2 inhalation administration, we develop a locally generated hyperbaric hydrogen platform by fabricating and leveraging crystalline u03B2-phase magnesium hydride (MgH2) as reservoirs of superior hydrogen-releasing capacity for tumor starvation therapy. The as-synthesized particles allow crystallization-controlled, prolonged H2 generation lasting days upon reaction with water, which further achieve in-situ overpressure (u0026gt; 1.8 atm) in response to the acidic tumor microenvironment (TME). We find that continuous exposure to single H2 of abundant supply can suppress energy metabolism in various types of tumor cells to inhibit proliferation and induce apoptosis. Moreover, the u03B2-MgH2 reservoir yielding significant intratumoral H2 is demonstrated in vivo for both local and systemic administration models, of marked metabolic function disruption, and excellent antitumor efficacy without causing systemic toxicity. Mechanistically, we distinguish that locally enriched H2 plays dual roles of impairing tumor aerobic glycolysis via downregulating HIF-1u03B1/GLUT1 axis, and eliciting mitochondrial damage associated with adenosine triphosphate (ATP) deprivation, which thereby synergistically block energy production for cancer anabolism. Collectively, our work delivers a proof of concept of "safe, local, long-acting" high-pressure hydrogen treatment modality to enable efficient cancer-selective starvation therapy.

Hydrogen (H2) antibacterial therapy has lately garnered burgeoning interest due to its unique characteristics as a non-antibiotic strategy for infection control. However, its bioefficacy remains controversial across infectious disease settings and its broad application is considerably constrained by the absence of delivery systems that enable localized and controlled H2 release. Here, we report a programmable H2 delivery platform by employing the modular assembly of block copolymer-grafted magnesium hydride (MgH2) microparticles. Modules with distinct H2 release kinetics were prepared by surface-initiated reversible addition-fragmentation chain transfer (RAFT) polymerization, which enabled robust polymer grafting and precise control over copolymer composition. Strategic cocktail assembly of modules with varying release profiles generated customizable H2 release programs tailored to specific therapeutic requirements. In acute infection and reinfection models, fast-, medium-, and slow-release assemblies showed distinct antibacterial activities. The fast-release formulation achieved the highest initial bacterial eradication rate of 99.9%, whereas the slow-release formulation effectively suppressed bacterial regrowth after reinfection. In an in vivo wound reinfection model, the slow-release formulation produced more than 90% antibacterial efficacy and significantly accelerated wound healing with a single administration, while the fast-release formulation showed limited therapeutic benefit.

Magnesium-rare earth (Mg-RE) alloys are pivotal for lightweight applications in aerospace and advanced engineering due to their high specific strength. However, manufacturing large-scale complex components via monolithic casting is challenging owing to defects such as RE oxides and shrinkage porosity, making fusion welding essential for both defect repair and structural joining. This review comprehensively examines recent advances in fusion welding of Mg-RE alloys, with emphasis on the interplay between their unique physicochemical properties and welding metallurgy. Various fusion welding methods suitable for Mg-RE alloys are compared and analyzed. Detailed characterization of joint regions reveals how thermal gradients and cooling rates govern phase evolution, grain morphology, and defect formation. Moreover, welding parameters and heat treatment strategies are systematically discussed for the microstructural configuration, especially for the inherent conflicts between grain coarsening in fusion zone and eutectic dissolution in heat-affected zone. Future research directions are also outlined. By correlating Mg-RE alloy properties with fusion welding processes, this review provides practical insights for designing reliable welded structures in critical applications.

Mitochondrial dysfunction and reactive oxygen species (ROS) overexpression are crucial factors inducing neuronal ferroptosis in cerebral ischemia/reperfusion injury (CIRI). Some therapeutics like RNAs and anti-oxidation drugs have been developed to regulate the functions of mitochondria, but are hardly delivered into brain effectively due to the blood-brain barrier (BBB). H2 has recently been verified able to overcome the BBB efficiently and has a unique wide-spectrum anti-oxidation/anti-inflammation effect, but sustainable, high-amount, and safe delivery of H2 into brain is still challenging currently. Herein, we develop an innovative H2 administration method of intraperitoneal injection of magnesium hydride microparticles (MgH2) with a high payload of hydrogen and a sustained hydrolytic H2 production behavior, achieving persistent and high-dose supply of H2 into the blood system as well as in the brain. In addition, we establish a novel CIRI rabbit model induced by transcarotid artery revascularization (TCAR), which leads to oxidative stress and subsequent ferroptosis in the brain's hippocampus. In this CIRI model, MgH2 treatment eliminates intracellular ROS, inhibits neuronal ferroptosis, and recovers mitochondrial dysfunction by stabilizing mitochondrial membrane potential, regulating mitobiogenesis, promoting neuronal energy metabolism, and activating the anti-oxidative pathway. All these findings demonstrate that MgH2 treatment provides a potential strategy for CIRI.

Precipitation strengthening typically enhances strength at the expense of ductility, giving rise to the strengthductility trade-off in magnesium-rare earth (Mg-RE) alloys. Erbium (Er), which exhibits relatively high solid solubility in Mg, offers great potential for strengthening and toughening Mg alloys. This study systematically investigates the influence of Er addition on the microstructure, mechanical properties, strengthening and toughening mechanisms of Mg-10Gd-xEr-0.2Zn-0.4Zr (x = 0, 1, 2, 4) (wt.%) alloys. The addition of Er causes a transformation of the eutectic phase from Mg5Gd to Mg3(Gd, Er) in the as-cast alloys, accompanied by an increase in the content of unexpected rare earth hydrides. Following appropriate heat treatment, a substantial amount of Er dissolves into the Mg matrix, resulting in pronounced solid solution strengthening. Additionally, a portion of Er participates in the precipitation process, significantly increasing the number densities and sizes of the beta' and beta 1 phases. Slip trace analysis indicates that Er addition remarkably promotes the activation of nonbasal slip, thereby enhancing homogeneous plastic deformation capability and contributing to improved ductility. First-principles calculations further confirm a substantial reduction in generalized stacking fault energy (GSFE) upon Er addition. The novel-developed Er-containing alloys demonstrate an excellent strength-ductility synergy, with the peak-aged alloy containing 2 wt.% Er showing superior room temperature mechanical properties: 257 MPa yield strength, 382 MPa ultimate tensile strength, and 8.2% elongation. This research provides important scientific insights into evading the strength-ductility trade-off in Mg alloys, which is critical for their broader application.

This work aims to design and validate the synergistic effects of ultra-high frequency and Y2O3 nanoparticles on sustainable corrosion resistance of plasma electrolytic oxidation (PEO) upon Mg alloys. Incorporation of Y2O3 nanoparticles into PEO coatings was efficient, with preferential growth on coating surface and within discharge channels. In particular, a high concentration of Y2O3 nanoparticles, up to 20.6 at.%, was observed in PEO coating prepared at the highest frequency (20 kHz) pulse current. Y2O3-based compounds such as YOOH and Y(OH)3 present within PEO coating exhibit superior electrochemical stability, thereby enhancing overall stability and corrosion resistance.

Additive manufacturing of Mg alloys via laser powder bed fusion (LPBF) has garnered increasing interest due to its capacity to produce superior mechanical properties compared to conventional as-cast alloys. However, the corrosion resistance of as-built Mg alloys relative to their as-cast counterparts remains poorly understood. In this study, a high-strength Mg-11Gd-2Zn-0.4Zr (wt.%, GZ112K) alloy is fabricated using both LPBF and semi-continuous casting techniques. The corrosion behavior of both as-built and as-cast alloys is systematically evaluated before and after solution and aging (T4 and T6) heat treatment processes. Electrochemical and immersion tests reveal the following corrosion resistance ranking: As-built < LPBF-T6 < LPBF-T4 < F-T4 < FT6 < As-cast. The as-built alloy, despite having finer grains and (Mg,Zn)3Gd eutectic secondary phase that enhance tensile properties, exhibits poorer corrosion resistance primarily due to the network distribution of (Mg, Zn)3Gd along grain boundaries, which lacks a corrosion barrier effect while increasing the cathode-to-anode ratio. During T4 treatment, the (Mg,Zn)3Gd phase transforms into blocky X phase along grain boundaries and lamellar long-period stacking ordered (LPSO) structures within the grains, reducing Volta potential differences, thereby improving corrosion resistance. However, the formation of beta ' aging precipitates in the LPBF-T6 alloy increases the micro-galvanic corrosion tendency, reducing corrosion resistance. This study underscores the critical role of T4 and T6 heat treatments in optimizing the corrosion resistance of additively manufactured Mg alloys.

With the rapid advancement of the hydrogen energy industry in recent years, Mg-based solid hydrogen storage materials and their associated storage and transportation systems have garnered significant global attention, leading to numerous groundbreaking studies and remarkable progresses. In the field of material design, high-performance nano Mg-based hydrogen storage materials and modified Mg-based hydrogen storage alloys have significantly enhanced the thermodynamic stability and kinetic properties of Mg and its hydrides. These advancements enable rapid hydrogen absorption and desorption at moderate or even room temperatures, paving the way for cost-effective applications. In terms of system development, the structural design and operational parameters of Mg-based solid hydrogen storage systems have been optimized through advanced simulation techniques and innovative design strategies, thus efficient thermal management of the storage system is achieved. In terms of engineering applications, the world's first ton-level Mg-based solid-state hydrogen storage and transportation trailer has been successfully launched. Additionally, multiple demonstration projects, including Mg-based solid-state hydrogen storage systems and hydrogen refueling stations, have been initiated worldwide. This paper reviews the significant research advancements in Mg-based hydrogen storage materials, focusing on four key areas: nanocrystallization, alloying, system development, and demonstration applications. It also summarizes relevant engineering demonstrations and applications in hydrogen energy storage and transportation, providing suggestions for the future research directions and potential applications.

In-situ formed TiC particles were introduced into α-Fe matrix as corrosion-resistant phases to enhance corrosion resistance against aluminum melt of the alloy. The effects of TiC content on the microstructure and corrosion behavior of Fe–TiC alloys were examined both experimentally and theoretically. The results indicate that eutectic Fe–6TiC alloy offers superior corrosion resistance to liquid aluminum, which is 7.5 times greater than that of H13 die steel. The long rod-shaped and granular eutectic TiC particles provide superior resistance to aluminum melt diffusion compared to blocky primary TiC. Moreover, these eutectic TiC particles improve the bonding strength of the intermetallic compound layer, inhibiting cracking, peeling, and dissolution of the corrosion layer. A novel theoretical numerical model is established to quantitatively account for the corrosion behavior of the ferrous alloys in aluminum melt, and the diffusion inhibition factor λ and dissolution inhibition factor ε are introduced in this work to quantitatively estimate the corrosion performance. Theoretical analysis demonstrates that Fe–6TiC eutectic alloy containing numerous long rod-shaped and granular eutectic TiC exhibits the best corrosion resistance.

Additive manufacturing (AM) of high-strength metallic alloys frequently encounters detrimental distortion and cracking, attributed to the accumulation of thermal stresses. These issues significantly impede the practical application of as-printed components. This study examines the Mg-15Gd-1Zn-0.4Zr (GZ151K, wt.%) alloy, a prototypical high-strength casting Mg-RE alloy, fabricated through laser powder bed fusion (LPBF). Despite achieving ultra-high strength, the GZ151K alloy concurrently exhibits a pronounced cold-cracking susceptibility. The as-printed GZ151K alloy consists of almost fully fine equiaxed grains with an average grain size of merely 2.87 μm. Subsequent direct aging (T5) heat treatment induces the formation of dense prismatic β' precipitates. Consequently, the LPBF-T5 GZ151K alloy manifests an ultra-high yield strength of 405 MPa, surpassing all previously reported yield strengths for Mg alloys fabricated via LPBF and even exceeding that of its extrusion-T5 counterpart. Interestingly, as-printed GZ151K samples with a build height of 2 mm exhibit no cracking, whereas samples with build heights ranging from 4 to 18 mm demonstrate severe cold cracking. Thermal stress simulation also suggests that the cold cracking susceptibility increases significantly with increasing build height. The combination of high thermal stress and low ductility in the as-printed GZ151K alloy culminates in a high cold cracking susceptibility. This study offers novel insights into the intricate issue of cold cracking in the LPBF process of high-strength Mg alloys, highlighting the critical balance between achieving high strength and mitigating cold cracking susceptibility.