The development of low-cost, high-performance Mg alloys is crucial to the industrial applications of large-scale production of Mg alloys. In this work, extruded Mg-5Bi-3Al alloy with excellent mechanical properties is successfully prepared by modifying the extrusion temperatures (240 ℃ and 300 ℃). The extruded alloy obtained ultra-high strength (yield strength = 380 MPa, ultimate tensile strength = 418 MPa) and excellent plasticity (elongation = 10.2%) at the extrusion temperature of 240 ℃, the main contributing factors are primarily attributed to the synergistic effect of ultrafine recrystallized grain size (~0.5 µm) and high density of Mg₃Bi₂ precipitates. Stacking faults within the sub-micron Mg₃Bi₂ phase are observed in the E240 alloy, confirming the plastic deformation capability of Mg₃Bi₂ phase. The effects of extrusion temperature on the microstructure, mechanical properties, and work-hardening behavior of the extruded Mg-5Bi-3Al alloys at room temperature are systematically investigated. The results suggest that decreasing the extrusion temperature can refine recrystallized grain size and Mg₃Bi₂ phase size, and the quantity of Mg₃Bi₂ phase is increased, while increasing the extrusion temperature can improve the degree of recrystallization and weaken texture. The work hardening rate is increased with the increased extrusion temperature, mainly due to the coarsening of grains and precipitates, and the weakening of texture. This work provides an experimental basis for preparing high-performance wrought Mg-5Bi-3Al alloys.

Bioinspired by Nepenthes, lubricant infused surfaces (LIS) have attracted widespread attention in the field of anticorrosion. However, the lubricant coating has some disadvantages such as complex construction processing and easy loss of oil phase in air or dynamic water phase. In this study, oleogel is infused into a lotus leaf inspired super-hydrophobic matrix to form an oleogel infused surface (OIS) for enhancing corrosion resistance of active Mg-Li alloy. For reserving oleogel, firstly, a facile one-step electrodeposition method is used to construct super-hydrophobic surface (SHS) composed by samarium/myristic acid complex micro-nano flower structure onto Mg-Li alloy. The coating exhibits excellent superhydrophobic property at a static contact angle of 160° by applying 30 V electrolysis for 30 min. The protection efficiency of single SHS highly relates with the metal itself. For short period immersion in water phase, SHS can afford protection to Mg-Li alloy. However, the long-term immersion will see the rapid failure of SHS, and the high activity of Mg-Li alloy is one main reason. We assume that SHS cannot be a good choice for protecting Mg-Li alloy. Then, a Nepenthes inspired liquid coating is formed by infusing oleogel into the micro-nano structure by a spin-coating method. The liquid coating performs prominent corrosion resistance with R_ct reaching as high as 1.51 × 10¹⁰ Ω cm². After the mechanical damage from the external environment, the liquid coating can realize self-repair through thermal assistance, and the liquid coating can still restore R_ct up to 1.24 × 10¹⁰ Ω cm² after healing. The corrosion resistance of the liquid coating remains strong by showing R_ct as high as 1.14 × 10⁹ Ω cm², even after immersion in representative corrosive 3.5 wt% NaCl solution for 30 d.