The inherent trade-off between mechanical strength and degradation rate critically hinders the development of high-performance degradable magnesium-based fracturing balls. To address this, this study successfully fabricated Fe3O4 particle-reinforced recycled AZ91 magnesium-based composites via solid-state synthesis and hot extrusion. The incorporation of Fe3O4 particles effectively induced particle-induced nucleation during dynamic recrystallization (DRX), significantly refining the grain structure and thereby enhancing the material's mechanical strength. Notably, the composite containing 5wt.% Fe3O4 achieved a high ultimate compressive strength of 513.9MPa while exhibiting a significantly accelerated degradation rate of 1590.8mm/y in a 3% KCl solution at room temperature—nearly three orders of magnitude faster than the unenhanced AZ91 alloy. This significant acceleration in degradation is primarily attributable to severe galvanic corrosion and coupling effects: Fe3O4 particles act as highly reactive cathodes with substantial potential differences relative to the matrix, while the introduction of Fe3O4 particles alters the precipitation behavior of the Mg17Al12 phase. Together with the surrounding Mg17Al12 phase, they form a “composite cathode region” that dramatically accelerates the anodic dissolution of the magnesium matrix. This study innovatively transforms the inherent corrosion sensitivity of solid-state recycled magnesium alloys into a functional advantage of controllable degradation. It provides new insights for designing high-performance degradable tool materials for oil and gas well fracturing operations, demonstrating significant potential for engineering applications.

Achieving a synergistic enhancement of strength and ductility in magnesium alloys remains a persistent challenge due to the intrinsic limitations of their hexagonal close-packed (HCP) crystal structure. In this work, it was found that the strength of ZGW511 alloy was improved to 381MPa and the elongation was increased to 12% by increasing the rolling speed to 2.5m/min at 220 °C. It is worth noting that when the rolling speed is 10m/min, the elongation of the alloy increases to 21% while maintaining the strength of 333MPa. During high-speed rolling, the temperature field and stress field of the alloy increased simultaneously. Based on the thermal-mechanical coupling effect, the recrystallization rate increased, and the grains were refined. As a result, the alloy retained a high work hardening rate while exhibiting significantly enhanced softening behavior during room-temperature tensile testing. Therefore, the strength and elongation of the alloy increased simultaneously. This work proposed a new strategy to achieve the synergistic improvement of strength and elongation in low rare-earth microalloyed magnesium alloys by optimizing a single rolling parameter.

The spatial distribution of particles strongly affects the stress state of composites during deformation. A clear understanding of particle flow behavior during forming, and of particle-matrix interaction mechanisms, is essential for controlling composite mechanical properties. However, the mechanisms by which particle distribution characteristics jointly influence matrix stress distribution and microcrack initiation remain unclear. In this study, power spinning was applied to the plastic forming of SiCp/AZ91 composite tubes. The stress state and particle flow behavior of SiCp during spinning were systematically investigated. The results show that during spinning deformation, the presence of SiCp promotes the redistribution of local stress toward the inner layer of the tube. This effect enhances the microstructural uniformity between the inner and outer layers. The multiaxial stress state drives SiCp to migrate from high-stress regions to low-stress regions. This behavior promotes uniform particle dispersion in the matrix. In addition, particle distribution significantly affects the matrix stress distribution and load transfer path. Therefore, based on strain gradient plasticity theory, the mechanisms of stress transfer and local microcrack nucleation under particle-matrix interaction were revealed. Increased particle spacing significantly improves stress distribution uniformity. It also expands the influence range of the particle deformation zone and reduces local stress concentration. Finally, the critical crack nucleation stress model indicates that a more uniform stress distribution enables multi-site crack initiation and stress release. This mechanism reduces the far-field stress at the crack tip, suppresses rapid crack propagation, and improves the fracture toughness of the composite material.

To examine the effects of different loading directions on mechanical behaviors and dynamic recrystallization of AZ31 magnesium alloy. Uniaxial hot compression experiments were conducted on the original AZ31Mg alloy at 0°, 15°, 30°, 45°, 60°, 75°, and 90° directions on the ND–RD plane. The results show that the sample compressed in the RD direction has a higher degree of dynamic recrystallization, and tensile twins promote the dynamic recrystallization behavior during the hot compression process. There are very few residual twins in the deformed samples. The compression behavior of samples with different orientations on the ND–RD plane shows anisotropy. The yield strength of the samples decreases first and then increases with the increase of the angle. The mechanical behavior of samples with different orientations shows anisotropy. The dynamic recrystallization mechanism of the samples is not affected by the spatial orientation. The dynamic recrystallization mechanism of the 0°, 45°, and 90° samples is all continuous dynamic recrystallization.

In this work, the SiCp/AZ91 composites prepared by freeze casting were subjected to hot extrusion, and then the microstructure, mechanical properties and fracture behavior were given and analyzed. The results showed that, after extrusion, the particle distribution of SiCp/AZ91 composites changed from lamellar to uniform distribution, which significantly improved the mechanical properties of the composites. With increasing volume fraction of SiCp, the thermal expansion coefficient of the as-extruded SiCp/AZ91 composites decreased significantly, accompanied by the improvement in elastic modulus. When the content of SiCp was 25 vol.%, the UTS and elastic modulus of the composite reached ~513MPa and ~91GPa, respectively, which exhibited the best combination of tensile strength and modulus. During the loading process, microcracks were more likely to initiate at the interface between the SiCp and magnesium matrix, and excessive SiCp could aggravate the stress concentration at the interface significantly, which led to the interconnection of microcracks and failure of the composite.

SiCp/Al-4.1Cu-xMg composites (x = 1.4, 2.0 and 2.6wt.%) were prepared by ultrasonic-assisted semi-solid stir casting. Among the investigated compositions, the as-homogenized SiCp/Al-4.1Cu-2.0Mg composite achieved the best overall mechanical properties, with a yield strength (YS) of 228.2MPa and an ultimate tensile strength (UTS) of 351.4MPa, which are at a leading level among reported cast Al matrix composites. The results show that Mg promotes the transformation of semi-coherent nanoscale Al2Cu precipitates into coherent Al2CuMg precipitates. Mg also participates in the reaction between SiCp and the Al matrix and promotes the formation of a MgAl2O4 reaction layer. This layer forms a semi-coherent interface with the Al matrix, thereby improving SiCp/Al interfacial bonding. During tensile deformation, strain first concentrates in the Al matrix and then induces crack initiation and propagation at the SiCp/Al interface. The addition of 2.0wt.% Mg improves interfacial bonding and increases matrix strength, which reduces the deformation mismatch between SiCp and the Al matrix and suppresses interfacial cracking. At 2.6wt.% Mg, the interfacial reaction layer thickens substantially and contains additional MgO and Mg2Si products. The resulting multiphase interface loses continuity and promotes rapid crack initiation and propagation, leading to premature failure. This work clarifies how Mg simultaneously regulates matrix precipitation, SiCp/Al interfacial reactions, deformation compatibility, and fracture behavior in cast SiCp/Al-Cu composites.

The influence of yttrium (Y) content on the mechanical properties and deformation behavior of Mg-Y alloys at room temperature (RT) and cryogenic temperature (CT) was systematically clarified. Increasing Y from 0 to 1.0 at.% markedly enhances strength and ductility at both temperatures, with the Mg-1.0Y exhibiting nearly double the tensile yield strength (TYS) and ultimate tensile strength (UTS) and a more than fourfold increase in elongation to fracture (EF) at CT compared with pure Mg. At RT, deformation in the low-Y alloy is dominated by basal slip followed by {101 2} tension twins, whereas higher Y content suppresses twinning and promotes the activation of non-basal slip, especially pyramidal ( c + a ) slip, leading to steadier lattice rotation and more homogeneous strain distribution. At CT, twinning and twin thickening are further promoted in the low-Y alloy, causing severe strain localization and early ductility loss, while the high-Y alloy retains a slip-dominated deformation mode with stable lattice rotation. Moreover, Y addition broadens slip transfer pathways from basal-basal to basal-prismatic/pyramidal slip transfers, enhancing intergranular strain compatibility and further improving ductility. These findings demonstrate that Y alloying shifts the deformation mechanism of Mg alloys from twinning-dominated to slip-dominated, providing a pathway to achieve superior mechanical properties. (c) 2026 Published by Elsevier Ltd on behalf of The editorial office of Journal of Materials Science & Technology.

This work reports a novel strategy for low-temperature, high-strength joining of Mg-Zn alloys based on a combination of rolled composite and diffusion reaction. A Mg/Zn filler preform was fabricated via rolling, wherein a non-equilibrium Mg7Zn3 phase with low melting point was in situ self-generated by lattice distortion induction and dislocation tube effect. The localized melting of the Mg7Zn3 phase triggers an overall gradient melting to achieve low-temperature, high-strength joining of Mg-Zn alloys. The exceptional strength originates from the alternating distribution structure of soft α'-Mg and hard Mg7Zn3 (MgZn2) phases. The method provides a new filler design strategy and theoretical insights for low-temperature high-strength joining of Mg alloys.

Shear spinning is an important method for metal shell forming. However, due to the poor plasticity of magnesium alloy, limited research exists on its spinning forming. Understanding the microstructure evolution of magnesium alloy during shear spinning is the key to realizing its controllable spinning forming. In this work, the microstructure, mechanical properties and fracture behavior of Mg-5Zn-1Gd-1Y-1Mn (ZGWM5111) alloy formed by shear spinning were investigated, and the dynamic recrystallization behavior and texture evolution during shear spinning were clarified. The results show that compared with the traditional plastic deformation, the thickness reduction of ZGWM5111 alloy in shear spinning is very small, and the microstructure can be changed significantly only by shear stress. The shear stress of the alloy varies during the spinning process, influencing both the recrystallization driving force and subgrain mobility. This leads to an evolution in the recrystallization mechanism, progressing from twin-induced to continuous, and ultimately to discontinuous dynamic recrystallization. Different from the existing research on magnesium alloys, the recrystallization grains of ZGWM5111 alloy are continuously refined during the spinning process, and the basal texture strength is also continuously enhanced. In addition, the mechanical properties of ZGWM5111 alloy were significantly improved after shear spinning, especially the elongation was doubled compared with that before spinning, which changes the fracture mode from brittle fracture to ductile-brittle mixed fracture.

Achieving simultaneous strength and ductility at cryogenic temperature (CT) remains challenging for Mg alloys. An extruded Mg-6Gd-1Zn (wt.%) alloy with bimodal grain structure and basal lamellar phases exhibits anomalous strength-ductility synergy at CT. Mechanical incompatibility between soft DRXed and hard unDRXed regions generates geometrically necessary dislocations (GND) accumulation and dominant hetero-deformation-induced (HDI) hardening. Basal lamellar phases intensify elastic and plastic incompatibility, steepening GND gradients and back stress at CT. The coupled bimodal grain structure and basal lamellar phases elevate local resolved shear stress, activating non-basal slip even in grains with low Schmid factors (SF), enabling enhanced cryogenic strength-ductility synergy.

In conventional magnesium (Mg) alloy brazing, the high brittleness of intermetallic compounds (IMCs) in fillers often results in poor processability, significantly affects the reliability and accuracy of brazed joints. This work proposes a novel preparation method for Mg alloy filler, improving the processing performance of the filler and significantly increasing the strength of brazed joints. The Mg/Al filler preform was prepared by rolling composite, and the preform in situ formed Mg/Al filler by diffusion reaction, simultaneously achieving high-strength precision brazing of Mg alloys with a maximum shear strength of 76 MPa. This outstanding shear strength is attributed to the soft and hard dual-phase heterogeneous structure of α-Mg/Mg17Al12 alternating distribution formed during the brazing solidification. The joint performance is significantly improved through coordinating the stress and strain distribution. Simultaneously, rapid diffusion of Al during brazing led to the sequential formation of the Al3Mg2 and the Mg17Al12 within the preform. Subsequently, Mg17Al12 occurs eutectic melting with residual Mg, ultimately triggering the complete melting of the preform to achieve efficient and precise bonding. This work provides a novel method for preparing fillers and offers theoretical insights into the efficient brazing of Mg alloys.

The anodic dissolution behavior of pure magnesium in sodium chloride solution was characterized using a synchronous online monitoring system. Concurrently, the film-forming magnesium was quantitatively characterized using a Thermal Gravimetric Analyzer (TGA). By combining these two analyses, the anodic reaction during the process of anodic polarization of magnesium was comprehensively described for the first time. This novel procedure allows for detailed examination of the quantitative relationship between film-forming magnesium and dissolved magnesium. To elucidate the anomalous hydrogen evolution, a plausible local active site mechanism was proposed. This mechanism suggests that uneven current distribution causes the local active dissolution, creating a potential difference that leads to the formation of micro-galvanic couples and subsequently anomalous hydrogen evolution.

TA1/2024/AZ31/2024/TA1 laminated composites (LMCs) were prepared using hot-pressing technology and then annealing at 300 °C for different time was carried out to regulate interface structure. The influencing mechanisms of interface microstructure evolution on the mechanical behavior and stamping formability of LMCs were discussed. The researches reveal that the basal texture of the Mg layer in LMCs annealed for 1 h is the weakest. The average Schmidt factor values of 1–100<11–20>cylindrical and 11–22<11–2–3>conical slip systems are relatively high, indicating they are easy to start, which is conducive to improving the plasticity of LMCs. As the annealing continues, both the Ti/Al and Al/Mg interface bonding strengths enhance first and then reduce, and the optimal bonding strengths of 47.80 N/mm and 4.24 N/mm are achieved when annealed for 1 h, respectively. Both the ultimate tensile strength and yield strength of LMCs reduce first and then enhance, reaching the minimums of 237.75 MPa and 189.02 MPa when annealed for 1 h, respectively. However, the changes of elongation (EL) and Erichsen value of LMCs are opposite, and they reach the maximum of 3.62

In this study, hybrid GNPs-GFs/Mg-3Zn-0.1Y composites with high strength, thermal conductivity, and modulus were prepared by combining liquid-phase dispersion and semi-solid-state followed by low-temperature extrusion at slow speed. The effect of extrusion temperature on the microstructure and the properties of the composites was investigated, the enhancement mechanism of mechanical properties was analyzed, and the effect of microstructure evolution on thermal conductivity was also investigated. The results showed that significant dynamic recrystallization and precipitation occurred in the composites after hot extrusion. The hot extrusion induced the GNPs and GFs to be orientated along the extrusion direction. This further effectively stripped the GNPs and GFs, reducing their layer number and improving their distribution in the matrix. The strength of the composites increases mainly due to fine-grain strengthening. The modulus enhancement is primarily associated with the uniformly distributed ultra-high modulus (similar to 1 TPa) GNPs in the matrix. After low-temperature and slow extrusion at 180 degrees C, the composites achieved strength-thermal conductivity matching with yield strength, tensile strength, elongation, and modulus of 336.7 MPa, 391.6 MPa, 6.2 %, and 55.4 GPa, respectively. The thermal conductivity reached 140.9 W/(mK). The solid bonding between the highly oriented GNPs-GFs and the magnesium matrix can effectively enhance load transfer, inhibit crack formation, reduce interfacial thermal resistance, and improve mechanical properties and thermal conductivity.

The 5 & micro;m 10 vol% SiCp/2024Al composites were fabricated by ultrasonic-assisted semi-solid stirring casting method, followed by high-temperature rolling at 480 degrees C. The effects of final rolling deformation on the microstructure, mechanical properties, work hardening, and dynamic softening behavior of SiCp/2024Al composites were systematically studied. The results show that the rolling deformation significantly promotes the synergistic refinement of the matrix and reinforcement phase. As the final rolling deformation increases, the grain size is refined from 8.28 & micro;m to 4.87 & micro;m, and both SiCp and Al2Cu phases undergo continuous fragmentation and refinement, with a marked improvement in spatial distribution uniformity. Additionally, the dislocation density in the Al matrix increases significantly, resulting in a simultaneous increase in both the work hardening and softening rates of the SiCp/2024Al composite. However, when the final rolling deformation reaches 40%, severe fragmentation of SiCp and Al2Cu phases accelerates the nucleation and propagation of microcracks in the matrix, leading to a reduction in both work hardening and softening rates. At a final rolling deformation of 35%, the composite achieves the optimal balance of microstructure and properties: the sizes of SiCp and Al2Cu phases are refined to 2.08 & micro;m and 2.16 & micro;m, respectively, the dislocation density increases to 6.86 & times; 1015 m-2, and the SiCp/ 2024Al composite exhibits excellent mechanical properties with a yield strength of 481.18 MPa and a tensile strength of 543.66 MPa. This study elucidates the intrinsic relationship between final rolling deformation and the synergistic regulation of microstructure and properties in SiCp/2024Al composites, providing an important theoretical basis for the design and processing of high-performance Al-based composites.

In this work, a novel SiCnp (SiC nanoparticles)/7075Al master alloy strategy was proposed to overcome the poor strength-ductility synergy in magnesium alloys. Mg–Al–Zn–Cu-SiCnp alloys were successfully prepared by introducing Al, Zn, Cu alloying elements and trace SiC nanoparticles (SiCnp, 0.05-0.15 wt%) into pure magnesium. The microstructural evolution and mechanical properties of the alloys with and without SiCnp addition were systematically investigated in both as-cast and solution-treated conditions. When the content of SiCnp increased from 0 to 0.15 wt%, the as-cast grain size of the Mg–Al–Zn–Cu-SiCnp alloy was remarkably refined from 189.8 μm to 90.0 μm. At the same time, the continuous reticular Mg17Al12 in the as-cast alloy were modified into dispersed short rod-like and granular phases. The Mg–Al–Zn–Cu-SiCnp alloy with 0.1 wt% SiCnp had the best comprehensive performance with yield strength (YS), ultimate tensile strength (UTS) and elongation (EL) of 105.3 MPa, 198.5 MPa and 4.3%, respectively. During solution treatment, SiCnp and thermally stable Al2Cu could synergistically pin grain boundaries and suppress grain growth. After solution treatment, the UTS and EL were further increased to 245.1 MPa and 9.5%, respectively. Thus, the SiCnp/7075Al master alloy strategy can be promising for the development of high-performance magnesium alloys.

Brazing of magnesium (Mg) alloys is critical for lightweight structural application, but the inherent brittleness of intermetallic compounds (IMCs) formed in conventional Mg alloy fillers severely limits joint reliability and precision. In this work, a novel in situ self-generating Mg-Zn filler was developed through rolling compounding and diffusion reactions to enable low-temperature precision brazing. The filler significantly enhances joint performance, achieving a maximum shear strength of 54.6 MPa. This exceptional strength originates from the formation of an α′-Mg/Mg7Zn3 (MgZn2) soft-hard biphasic heterostructure during brazing solidification. The ductile α′-Mg phase effectively blunts crack tips, suppresses crack propagation, and relieves stress concentration in the hard-brittle Mg7Zn3 (MgZn2) phases, improving overall toughness and reliability. Meanwhile, rapid Zn diffusion during brazing induces atomic size mismatch within the α-Mg matrix, generating lattice distortion and dislocation proliferation. These structural defects lower the nucleation barrier of IMCs and promote the formation and localized melting of Mg7Zn3, which triggers gradient melting of the filler and enables effective low-temperature joining. This work provides a new filler design strategy and theoretical insights for advancing precision brazing of lightweight Mg alloys.

This work investigates the effect of multi-directional forging (MDF) temperature on the dynamic precipitation, dynamic recrystallization (DRX), work hardening and softening behavior of Mg-5Zn-1Gd-1Y (ZGW511) alloy. The addition of rare earth (RE) elements restricts Zn diffusion due to their drag effect and low diffusivity, promoting in-situ intragranular precipitation. The W phase (Mg3Zn3RE2) with lower Gibbs free energy preferentially undergoes dynamic precipitation. And the pinning effect of the intragranular precipitated W phase on the dislocation inhibits the nucleation of DRX. Increasing forging temperature promotes Ostwald ripening, enlarging W phase particles and enhancing their pinning effect, leading to a gradual decrease in DRX volume fraction. Concurrently, the reduced dislocation density and increased grain size weaken work-hardening and softening. While the intragranular W phase hinders the dislocation motion and triggers local dislocation accumulation, its periodic distribution forms sub-micron dislocation channels that facilitate the transfer of dislocation slip, resulting in the increasing Delta sigma p/sigma 0 with the increasing number of stress relaxation cycles.

In this work, the Mg-5Zn-1Gd-1Y (ZGW511) alloy was prepared and subjected to multidirectional forging (MDF) at 350 degrees C. The effects of cumulative strain on the microstructure, mechanical properties, work hardening and softening behavior of ZGW511 alloy were investigated. The results show that the Mg2(Zn, Gd, Y) phase is precipitated in the grain at the initial stage of forging, and gradually changes from short rod to spherical W phase during the MDF forging process. With the increase of the cumulative strain, the W phase is refined and the deformation microstructure decreases, which weakens the promotion of DRX nucleation, but the DRX mechanism changes from DDRX mechanism to CDRX mechanism due to the gradual increase of DRX induced by cumulative strain. After MDF, the microstructure uniformity of ZGW511 alloy was significantly improved, the hardness difference was reduced, the ultimate tensile strength was increased from 196.77 MPa to 271 MPa, and the plasticity was increased from 7.7 % to 15.9 %, realizing the synergistic improvement of strength and plasticity. After MDF, the work hardening rate of ZGW511 alloy increases accompanied with the decrease of the softening rate in the early stage of deformation, both of which increase with the increasing cumulative strain. When the cumulative strain was increased from 2.4 to 4.8, the work hardening rate and softening rate decreased due to the increase of VR/VD (where, VR is the volume occupied by DRXed grains and VD is the volume occupied by deformed grains) value and the growth of DRXed grain.