Considering the advantage of safety and cost, designing a Mg–air battery with high capacity has been highly sought in recent years. However, self-corrosion and passivation of Mg anode critically reduce discharge performance, hindering the large-scale application of Mg–air batteries. In this study, a series of as-cast and extruded Mg-3In-xCa alloys were successfully fabricated. Microstructures, chemical composition, and discharge performance were investigated to optimize the content of Ca (x). The selected Mg–air battery with Mg-3In-3Ca alloy as anode represented the best battery performance, including 0.738 V of discharge voltage, 1323.92 mAh g⁻¹ of specific capacity, and 61.74% of anodic efficiency at discharge current density of 30 mA cm⁻². All of its parameters were vastly superior to pure Mg–air battery. In addition, the synergistic effects of In and Ca on promoting electrode properties were evaluated in detail, using SEM and electrochemical analysis, which is expected to trigger follow-up research in designing high-performance Mg–air batteries.

To provide insight into the interface structure in Ti particle-reinforced Mg matrix composites, this study investigates the inherent Mg/Ti interface structure formed during the solidification of supercooled Mg melt on a (0001)Ti substrate using ab initio molecular dynamics (AIMD) simulations and density function theory (DFT) calculation. The resulting interface exhibits an orientation relationship of ${\left(0001\right)}_{\mathrm{Mg}}{//\left(0001\right)}_{\mathrm{Ti}}$ with a lattice mismatch of approximately 8%. Detailed characterizations reveal the occurrences of ${\left(0001\right)}_{\mathrm{Mg}}$ plane rotation and vacancy formation to overcome the lattice mismatch at the inherent Mg/Ti interface while allowing Mg atoms to occupy the energetically favorable hollow sites above the Ti atomic layer. The atomic diffusion behaviors of rare-earth elements Gd and Y at the Mg/Ti interface was examined using the climbing image nudged elastic band (CI-NEB) method, demonstrating a strong segregation tendency towards the interface promoted by the inherent interface structure. Additionally, the calculated Griffith work indicates enhanced interfacial adhesion due to the segregation of Gd and Y, which is beneficial for the mechanical properties of the composite.

This study examines the microstructure, corrosion resistance, and electrochemical behavior of Fe–20Cr–18Ni–6Mo–0.8Cu–0.2N–La alloys after heat treatment at different temperatures. The results show that heating the alloy to 1200 °C for 1 h leads to the dissolution of second-phase particles, and the undissolved precipitation is Mo-rich phase σ-FeCrMo. Loss-in-weight analysis indicates that corrosion resistance is better at 75 °C than at 50 °C, with the 0.5 wt% alloy showing the lowest corrosion rate (75 °C: 0.0116 mm/a). Electrochemical tests indicate the 0.5 wt% La alloy shows the lowest corrosion current densities of 5.272 × 10 ⁻⁷ A/cm ² at 50 °C and 1.183 × 10 ⁻⁶ A/cm ² at 75 °C, demonstrating superior corrosion resistance as a cathode. Surface roughness analysis shows that the surface roughness is decreased after alkaline seawater (ASW) corrosion at 75 °C. This study highlights the potential of austenitic stainless steels as cathode materials for hydrogen (H ₂ ) production from seawater electrolysis (SWE).

The formation criteria of the LPSO phase are important for the design of long-period stacking-ordered (LPSO) Mg alloys. This work focuses on Type I LPSO Mg-Y-X alloys and attempts to explore the formation criteria of the LPSO phase from the perspective of liquid-solid correlation. With the aid of ab-initio molecular dynamics simulation, liquid Mg-Y-X alloys are investigated to obtain the common liquid characteristics from the reported Type I LPSO Mg-Y-X alloys. Following the liquid characteristics, a new Type I LPSO alloy, i.e., Mg-Y-Au, is experimentally confirmed. The discovery of a new Type I LPSO alloy supports liquid–solid correlation, and hence, the formation criteria of the LPSO phase in Type I LPSO alloys can be developed based on the common liquid characteristics of Type I LPSO Mg-Y-X alloys as follows: X should result in the reduction in equilibrium volume and cohesive energy; Y should repulse Y and be attracted by both Mg and X, and X should be repulsed by both Mg and X; X should enhance the threefold and fourfold symmetries and weaken the fivefold and sixfold ones so that the local structural symmetries are distributed close to liquid pure Mg.

It is well known that residual stress is detrimental to mechanical properties of metal materials. This paper investigated the relief of residual stress during long-time natural aging as well as its influence on tensile properties of partial age-hardenable Al alloys. It was found that uniform elongation and ultimate tensile stress were increased after a long-time natural aging of T6 heat-treated 2024, A356, 6063 and 6061 alloys. For example, uniform elongation and ultimate tensile stress of 2024 alloy were respectively increased from 10.2% and 496.7 MPa to 11.1% and 507.5 MPa. According to fracture behavior observation for 2024 and A356 alloys, cracks or/and voids could generate from micron-sized secondary particles or particle/α-Al interface in matrix, which led to fracture of tensile samples eventually. And reduced residual stress during natural aging delayed formation of the cracks or voids based on stress distribution analysis, which led to an increase in uniform elongation and tensile stress of Al alloys.

The appearance of the ε phase during the welding process can severely weaken the welding strength of dissimilar metals of Mg-Zn-Al alloy systems. An understanding of the accurate phase diagram, especially the equilibrium phase relation around the ε phase, is thus of particular importance. However, the phase interrelation near the ε-Mg₂₃(Al, Zn)₃₀ phase has not yet been fully studied. In this work, the local phase diagrams of the ε phase and its surrounding phases in the Mg-Zn-Al system are systematically determined by experimental investigation and thermodynamic verification. Five Mg-Zn-Al alloys and one diffusion couple were fabricated and analyzed to get accurate phase constituents and relationships adjacent to ε phase. The current experimental data obtained from Scanning Electron Microscope (SEM), X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC), and Electron Probe Micro Analysis (EPMA) were further compared with the thermodynamically computed phase relations around ε phase for verification, showing good agreements. Several important conclusions are drawn based on current experimental work, which can provide supporting information for the follow-up studies on ε phase in the Mg-Zn-Al alloy systems.