Magnesium (Mg) and its alloys are currently the lightest structural metals in engineering applications, widely used in aerospace, defense technology, transportation and electronic 3C fields. Plastic deformation is a commonly used method to improve the comprehensive mechanical properties of Mg alloys. Multi-directional forging (MDF), as a severe plastic deformation (SPD) method, is considered as an effective technology for manufacturing large-sized Mg alloys with high strength and toughness. This paper outlines the process principle of MDF and analyzes the microstructure evolution, texture and mechanical properties of Mg alloys processed by MDF. The effect of deformation parameters, such as deformation temperature, accumulative strain and strain rate, and alloying elements on grain refinement, second phase evolution and texture are discussed systematically. Additionally, recent research highlights the Mg alloys with high strength and toughness processed by MDF. Furthermore, the contribution of grain refinement, precipitation, solid solution and texture-strengthening mechanisms on the mechanical properties are revealed. Finally, we conclude the research progress, analyze the shortcomings in development, and recommend further prospects. We hope this review will inspire new ideas on the development of Mg alloys with a high strength and MDF process.

In the current work, cyclic expansion extrusion with an asymmetrical extrusion cavity (CEE-AEC), as a relatively novel severe plastic deformation method, was applied to fabricate an AZ31B magnesium alloy plate with a size of 50 × 100 × 220 mm, and the resultant microstructure, texture development, and mechanical properties were systematically investigated. A refined and homogeneous grain structure was achieved after three passes of deformation due to dynamic recrystallization. The grain refinement degree in comparison to as-cast alloys was more than ~96%. With the increasing number of CEE-AEC passes, a basal inclination texture was gradually formed, with the basal planes inclined ~45° from the transverse direction to the extrusion direction, which could be attributed to the introduction of an asymmetrical extrusion cavity that led to an increasing Schmid factor for the activation of basal slip systems. The comprehensive mechanical properties were improved by successive multi-passes of CEE-AEC processing, especially due to the ductility reaching to 30.0 ± 1.3% after three passes of deformation. The competition between the grain refinement and texture modification were the main strengthening mechanisms.

This study investigates the mechanical response characteristics and damage evolution behavior of TC4 alloy through quasi-static/dynamic coupled experimental methods. Quasi-static tensile tests at varying temperatures (293 K, 423 K, and 623 K) were conducted using a universal testing machine, while room-temperature dynamic tensile tests (strain rate 1000–3000 s⁻¹) were performed with a Split Hopkinson Tensile Bar (SHTB). Key findings include the following: (1) Significant temperature-softening effect was observed, with flow stress decreasing markedly as temperature increased; (2) Notch size effect influenced mechanical properties, showing 50% enhancement in post-fracture elongation when notch radius increased from 3 mm to 6 mm; and (3) Strain-hardening effect exhibited rate dependence under dynamic loading, with reduced hardening index within the tested strain rate range. The Johnson–Cook constitutive model and failure criterion were modified and parameterized based on experimental data. A 3D tensile simulation model developed in ABAQUS demonstrated strong agreement with experimental results, achieving a 0.97 correlation coefficient for load–displacement curves, thereby validating the modified models. Scanning electron microscopy (SEM) analysis of fracture surfaces revealed temperature- and strain rate-dependent microstructural characteristics, dominated by ductile fracture mechanisms involving microvoid nucleation, growth, and coalescence. This research provides theoretical foundations for analyzing Ti alloy structures under impact loading through established temperature–rate-coupled constitutive models.

Reducing shock wave drag and heat flux is crucial for improving the performance of hypersonic vehicles. As an efficient flow control technology, the plasma synthetic jet actuator (PSJA) has attracted considerable attention in the field of shock control. A novel discharge strategy is proposed in this study to enhance the control effect on the flow field by performing multiple discharges during the blowing phase of the PSJA. The effect of the novel discharge strategy on the control of the flow field is investigated, and the effects of the discharge interval, the discharge energy ratio, the total discharge energy, and the number of discharge on the drag and heat reduction are analyzed in detail. The results show that a shock-breaking effect is formed due to the effect of plasma synthetic jet generated after the first discharge on the shock. The plasma synthetic jet generated by the subsequent discharge can act on the bow shock with lower dissipation, resulting in a higher velocity of the jet. The duration of shock detachment is prolonged and the control effect of the flow field is enhanced. The subsequent discharge is triggered when the discharge region density reaches its peak, and the control effect of the flow field is the best. The higher discharge energy ratio enhances drag reduction, which can be improved by 2.44%. The lower discharge energy ratio is more beneficial to heat reduction, which can be increased by 9.55%. For different total discharge energy, the drag and heat reduction achieved are optimal when using a two-discharge strategy.