Chao Xu

A processing route combining electropulsing-assisted stress-relief annealing at 300 °C for 5 min, 20% cold rolling, and final electropulsing-assisted annealing was investigated for hot-rolled Mg–Y–Nd–Gd–Zr alloy. The final treatment at 400 °C for 20 s produced an ultimate tensile strength of 283.0 MPa and an elongation of 14.7%, retaining 97.2% of the cold-rolled precursor strength while increasing elongation from 3.8% to 14.7%. Electron backscatter diffraction identified a low-orientation-spread grain fraction of 47.7% and a retained {10-12} tensile twin-boundary fraction of 12.2%. Transmission electron microscopy revealed locally aligned dislocations and wall-like configurations. First-principles calculations for α-Mg represented the thermal component through temperature-dependent lattice expansion and the electrical component through changes in electronic occupation. Lattice expansion and electron addition reduced the calculated basal slip barriers, whereas electron removal increased them. The combined results associate the favorable tensile response with recovery and partial recrystallization of a deformation-strengthened precursor, together with retained twin interfaces and organized dislocation structures. This multi-step route provides a processing approach for restoring ductility while preserving substantial strength in Mg–Y–Nd–Gd–Zr alloy.

A blockchain address serves as the unique identifier for users within a blockchain network. While existing blockchain solutions typically employ the Elliptic Curve Digital Signature Algorithm (ECDSA) for address generation, researchers including Ruimin Wang and Jisheng Dong have proposed alternative schemes based on SM9 identity-based cryptography to circumvent the inherent limitations of the Public Key Infrastructure (PKI). However, while preserving the address privacy of transacting parties, these schemes lack traceability, creating vulnerabilities to Sybil attacks in application scenarios such as voting. To address this issue, this paper proposes a novel blockchain address generation scheme based on SM9 identity-based cryptography. Incorporating the concept of hierarchical cryptography, we design a two-tier key derivation structure to guarantee the address privacy of both transacting parties. Furthermore, the generation of derived keys integrates secret sharing technology, thereby achieving source traceability with provable linkage. Provided that participants have registered a legitimate identity (blockchain address), utilizing the proposed scheme to construct derived addresses effectively prevents them from launching Sybil attacks via these derived addresses. The security properties of the proposed scheme—including uniqueness, unpredictability, pseudonymity, traceability, and Sybil resistance—are formally proven under the random oracle model. Finally, theoretical analysis and experimental results demonstrate that, alongside enhanced security (100% Source Tracing Accuracy), the proposed scheme incurs no significant increase in key and address lengths compared to existing solutions, with only a marginal increase in computational overhead.

Nowadays, magnesium (Mg) alloys are increasingly being considered as a promising lightweight structural material because of their inherent low density and high specific strength. However, the broad application of most Mg alloys is limited by their poor strong-ductility trade-off at room temperature. At present, tailoring the bimodal grain structure (BGS) has the potential to concurrently enhance strength and ductility. Therefore, in order to achieve controllable preparation of BGS, recent research on the formation of Mg alloy with BGS was evaluated from the perspectives of alloy design, initial microstructure of billets, and process parameter. In addition to summarizing the role of BGS in synergistically improving strength and ductility, the influence of BGS on other properties of Mg alloys was also summarized, such as tension-compression yield asymmetry, corrosion resistance, fatigue performance, and fracture toughness. The research progress in controlling BGS provides valuable insights into the design and production of high-performance Mg alloys.

T6 aging, involving solution treatment and artificial aging, is a widely adopted strengthening method for magnesium alloys due to its proven effectiveness. However, the integration of three or more sequential thermal treatments has been explored only sparingly, primarily due to the challenges associated with optimizing such multi-parameter processing systems. This study demonstrates that integrating a 12 h deep cryogenic treatment (DCT) before aging in a Mg–Al–Ca–Mn alloy optimizes mechanical performance, achieving a tensile strength of 343 MPa and 27.3% elongation. Microstructural analysis, based on electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM), reveals that the strength enhancement results from ~29 nm precipitate refinement, elevated dislocation density, and nanoscale sub-grain formation, while the ductility gains stem from the activation of non-basal slip systems and the suppression of microcrack propagation. These synergistic mechanisms enable superior strain accommodation, providing a clear framework for DCT-enabled sequential heat treatment design in high-performance magnesium alloys.

Magnesium (Mg) alloys are prized as the lightest structural materials but often suffer from a strength–ductility trade-off that is particularly challenging for applications demanding high thermal conductivity. Aiming to resolve this issue, rolled ternary Mg-0.9Mn-1.9Ce (wt.%) alloy sheets were designed and fabricated, and the influence of rolling strain on optimizing the property balance was systematically investigated. The cast alloy was homogenized and rolled to two accumulated strains to obtain S10 (90%) and S20 (95%), followed by microstructure characterization and mechanical/thermal evaluation. Compared with S10, S20 developed finer, more equiaxed grains and a weaker basal texture via enhanced dynamic recrystallization; concurrent fragmentation and uniform dispersion of second-phase particles further contributed to strengthening. Consequently, S20 achieved 14.2% and 13.7% increases in yield and tensile strengths, respectively, with a slight improvement in elongation, while retaining high thermal conductivity (134.4 W·m⁻¹·K⁻¹ vs. 138.1 W·m⁻¹·K⁻¹ for S10). The minimal conductivity penalty is attributed to the low solute level in the α-Mg matrix, which limits electron scattering. These results provide experimental and mechanistic guidance for developing rolling Mg alloys that combine high mechanical performance with excellent thermal efficiency.