Applications of Magnesium Alloys in the Aerospace Industry

—The Weight-Reduction Revolution: From Gram-Class Satellite Mounts to Ton-Class Missile Casings

I. Why Magnesium?

With a density of 1.74 g/cm³—just one-fourth that of steel and two-thirds that of aluminum—magnesium has a specific strength more than 30% higher than aluminum alloys, superior vibration damping properties compared to titanium alloys, and electromagnetic shielding performance comparable to copper. When aircraft manufacturers measure costs in “grams," magnesium alloys become the natural choice: reducing a fighter jet’s weight by 15% can shorten its takeoff roll distance by 15% and increase its range by 20%; for every 1 kg of weight saved in a satellite’s structure, the launch vehicle can carry 50 kg less propellant, and ground support structures can save an additional 100 kg.

II. Application History: A Rocky Road, but Taking Off Again

In 1920, magnesium alloys were used in the frames of German Zeppelins; during the Cold War, the U.S. and the Soviet Union extensively used magnesium alloys in bombers and missile casings, but their short service life and corrosion issues were overshadowed by wartime demands. In the 1970s and 1980s, aluminum alloys rose to prominence, causing a sharp decline in the use of magnesium alloys. In the 1990s, the demand for automotive weight reduction drove technological breakthroughs—high-purity alloys, micro-arc oxidation, and chemical plating successively matured—prompting the aerospace industry to turn its attention back to magnesium alloys, ushering in a “second spring."

III. Magnesium’s Presence in Today’s Skies

1. Fixed-Wing Aircraft

• The C919 uses ZK60 magnesium alloy for seat frames, reducing weight by 18 kg per aircraft and saving 35,000 liters of fuel annually;
• The Boeing 787 extensively uses the Elektron®43 magnesium-rare earth alloy for cabin crossbeams and electronic equipment brackets, replacing titanium alloy parts and reducing weight by 25%.

2. Helicopters

The new-generation “King of the Plateaus" helicopter uses a Mg-Gd-Y-Zn-Zr rare-earth magnesium alloy primary load-bearing frame, reducing weight by 18% compared to the original aluminum alloy and increasing the cruising ceiling by 300 m.

3. Missiles and Drones

• Germany’s Taurus KEPD-350 stand-off missile uses 100 kg of magnesium alloy (GW83, ZK61) throughout the missile for reinforcement frames and control surfaces, with a range of 350 km and a Mach number of 0.9;
• The casing of a certain domestic 145-mm-caliber light missile uses seamless magnesium alloy extruded tubes, reducing weight by 30% compared to aluminum casings of the same specifications and increasing range by 12%.

4. Satellites and Spacecraft

• The electronics enclosure of the Chang’e-3 mission uses monolithic magnesium alloy panels, reducing weight by 13 kg and integrating thermal control, electrical conductivity, and corrosion resistance through micro-arc oxidation;
• A remote sensing satellite launched in 2022 incorporated magnesium-lithium alloy brackets, embedded components, and satellite spacers in mass production, reducing the satellite’s total weight by 8% and directly increasing the payload by 15 kg.

IV. Key Technologies: Ensuring Reliable Flight of Magnesium

1. Alloy Upgrades

Mg-RE (rare earth) alloys maintain a creep strength of 200 MPa at 300 °C; Mg-Li alloys have a density reduced to 1.5 g/cm³ and a modulus of elasticity increased by 20%, making them specifically suitable for space optical brackets.

2. Corrosion and Protection

A micro-arc oxidation + electrochemical Ni-P-graphene composite coating achieves a salt spray life of 1,000 h with thermal conductivity loss <5%, solving corrosion and thermal control challenges throughout the satellite’s 15-year service life.

3. Forming and Joining

• Vacuum-assisted semi-solid forming (Thixomolding) enables the production of complex, thin-walled shells as thin as 0.5 mm, with a first-pass yield rate of 95%;
• Laser brazing overcomes the challenge of dissimilar magnesium-steel joints, tripling fatigue life, and is used in engine mounting brackets.

V. China’s Path: From a Resource-Rich Nation to an Aerospace Powerhouse

China ranks first in the world in both magnesium reserves and production. The Beijing Satellite Manufacturing Plant, the Changsha New Materials Research Institute of China Aerospace Science and Industry Corporation, and the Shanghai Jiao Tong University team have established an integrated chain encompassing “alloy design—process optimization—surface treatment—on-board verification":

• The use of magnesium alloys in aerospace applications is projected to reach approximately 20,000 metric tons in 2024, with plans to exceed 50,000 metric tons by 2030;
• The National Key Research and Development Program allocates 300 million yuan annually, focusing on “bottleneck" components such as 20-metric-ton-class large magnesium alloy module sections and reusable rocket fuel tanks.

VI. Future Outlook

Reusable launch vehicles, hypersonic aircraft, and eVTOL urban air mobility will propel magnesium alloys to new heights:

• Additive manufacturing (WAAM) prints 1-meter-class monolithic magnesium alloy control surfaces at a rate of 1.5 kg/h, achieving a 35% weight reduction;
• AI-driven alloy design will compress the development cycle for new grades from 3 years to 6 months;
• Green closed-loop recycling technology reduces the carbon footprint of recycled magnesium to <2 kg CO₂/kg, aligning with carbon neutrality goals.

From gram-level satellite mounts to metric-ton-class missile casings, magnesium alloys are proving themselves as the “lightest metal"