Foamed Magnesium Alloy

Foamed Magnesium Alloy:A Novel Metal Material

A Novel Metal Material

Foamed magnesium alloy, also known as porous magnesium alloy, is a new type of metal material with an internal structure composed of numerous interconnected pores, resembling a "metal sponge." This material is characterized by its lightweight nature and high specific strength. As a functional material, it possesses multiple physical properties such as porosity, vibration damping, sound absorption, noise insulation, heat insulation, impact energy absorption, and electromagnetic shielding.

Compared with porous materials produced by powder metallurgy, porous foamed magnesium alloy has larger pore sizes and more interconnected pores. The pore diameter of foamed magnesium alloy ranges from 0.3 to 10 mm. The porosity varies depending on the specific type of foamed magnesium alloy, generally within the range of 70% to 80%. As porosity increases, the density of the material decreases, typically reaching one-third to one-quarter of the volume-equivalent solid metal. For instance, foamed magnesium alloy with a porosity of 74% has a density of less than 0.49 g/cm³, making it extremely lightweight. 

Applications of Foamed Magnesium Alloy

As a Structural Material

Foamed magnesium alloy is widely used in structural applications due to its low density, high stiffness, sound insulation, heat insulation, and energy absorption properties. Additionally, it does not emit toxic gases when heated. It finds applications in intelligent machinery and the rail transportation industry, such as in railway carriages and containers for thermal and acoustic insulation, energy absorption, and anti-toxicity components.

A Functional Material

Foamed magnesium alloy is used in multiple functional applications:

Energy-absorbing and damping materials – for impact protection and vibration reduction.

Sound absorption materials – for reducing noise pollution.

Electromagnetic shielding materials – for blocking electromagnetic interference.

Heat exchange and thermal insulation materials – for controlling temperature fluctuations.

Filtration materials – for separation and purification processes.

Leveraging its sound insulation, sound absorption, and energy absorption capabilities, foamed magnesium alloy is applied in urban construction for environmental protection, such as soundproof barriers. In the automotive industry, it is used in energy-absorbing components and soundproofing parts, such as bumpers and mufflers.

Its low density, high stiffness, and low thermal conductivity make it ideal for use in energy-efficient buildings, including insulated walls, fireproof doors, and energy-saving mobile housing.

Applications in the Machinery, Robotics, and Aerospace Industries

Foamed magnesium alloy’s lightweight nature, combined with its heat insulation, sound insulation, vibration reduction, and energy absorption capabilities, makes it valuable in mechanical engineering, robotics, and the aerospace industry. It is widely utilized for weight reduction, insulation, damping, and impact energy absorption components in these sectors.

Electromagnetic Shielding Applications

Foamed magnesium alloy provides high shielding effectiveness, reaching up to 110 dB in the frequency range of 300 MHz to 3 MHz, making it highly effective in blocking electromagnetic waves, X-rays, infrared radiation, and various forms of nuclear radiation. This makes it widely applicable in fields related to electromagnetic information security. Additionally, it is used in manufacturing electromagnetic shielding cabins to prevent information leakage and suppress electromagnetic pulse interference.

Ballistic Protection and Impact Resistance

Beyond its extremely low weight, foamed magnesium alloy exhibits excellent bulletproof and impact resistance. It can absorb 75% of a bullet’s kinetic energy, offering protection against heavy machine gun and sniper rifle fire while effectively attenuating explosive shock waves and high-intensity sound waves. With a porosity of 70%-80% and a density only one-third to one-quarter of conventional metals, foamed magnesium alloy possesses exceptionally high specific stiffness and outstanding seismic resistance.

Manufacturing Methods

The production of foamed magnesium alloy involves various methods, including melt foaming, powder metallurgy, and casting, allowing for industrial-scale production with different sizes, pore diameters, and shapes.

Future Prospects

Due to its unique properties, foamed magnesium alloy is considered a key material for future high-performance applications, particularly in lightweight structures, thermal insulation, protective materials, and electromagnetic shielding. It holds immense potential across a wide range of industries.