Since 2000, magnesium alloys have ushered in a glorious "golden 25 years". In the 20th century, magnesium was merely "the third structural metal in the laboratory". But now, it has become the common choice for automobiles, bicycles, high-speed trains, aircraft, mobile phones, robots, and even future electric vertical take-off and landing aircraft (eVTOL). The performance, processing technology and application scenarios of magnesium alloys have all achieved a leap from "usable" to "very useful", and then to "essential".
Compared with other materials, magnesium alloys possess low density, high shock absorption, excellent electromagnetic shielding, noise reduction performance and processing-recycling advantages. Despite the processing challenges, their wide application has made them a hot topic in materials science research.
The industrial grade magnesium can reach a purity of over 99.99%. However, pure magnesium itself cannot be used as a structural material. To enhance the properties of pure magnesium, alloying elements such as aluminum, zinc, lithium, manganese, zirconium and rare earth can be added to form magnesium alloys, which have high strength and are widely used in the field of structural materials. Depending on different alloying elements, magnesium alloys can be classified into five series: Mg-Al (magnesium-aluminum alloy), Mg-Zn (magnesium-zinc alloy), Mg-Mn (magnesium-manganese alloy), Mg-Zr (magnesium-zirconium alloy) and Mg-RE (magnesium-rare earth alloy).
Magnesium alloys, as the lightest metal structural materials, have gained popularity in the aerospace industry due to their low density, high specific stiffness, excellent thermal conductivity, and corrosion resistance. They have become the "favored choice" in this field. From Mr. Qian Xuesen's emphasis on "every gram of weight reduction is a contribution", to the current industry trend where the global market size is expected to exceed 2.4 billion US dollars, the application value of magnesium alloys runs through numerous fields such as aerospace and aviation. In the future, magnesium alloy materials will undoubtedly play a key role in technological research and development in fields such as aerospace and new energy vehicles.
The future development of the magnesium alloy industry will be achieved in three steps:
1. Material side: Multifactorial microalloying with rare earth/aluminum/zinc, with tensile strength exceeding 350 MPa, and corrosion resistance in salt spray test lasting over 1000 hours, achieving "unrustic magnesium".
2. Process side:
• High vacuum die casting + real-time vacuum extraction technology, with shrinkage rate reduced to 0.2%, and yield rate matching that of aluminum alloys;
• High-speed extrusion mold steel (H13 + Nb microalloy) has a lifespan increased by 2 times, and extrusion speed raised to 30 m/min.
3. Industry side:
• Establish a closed-loop recycling system for magnesium alloys (recycled magnesium energy consumption is only 5% of the original magnesium), securing long-term cost advantages;