From Microscopic to Macroscopic: The Wonderful World of Foamed Metals
Imagine a piece of metal with an intricate network of pores, with air occupying more than 90% of the space – this is the uنيque structure offoamed metals. This is the unique structure of foam metal. It retains the high strength and corrosion resistance of metal, but because of the pore structure, it has gained ultra-lightweight characteristics (density of only 1/5 of conventional metal) and a large specific surface area. This characteristic of “flexibility and rigidity” makes it a “universal building block” in the hands of scientists: by adjusting the porosity and skeleton configuration (e.g., biomimetic Kelvin honeycomb, helical Gyroid structure), it is possible to customize the properties of thermal conductivity, energy absorption, catalysis, etc., as if for different scenarios and applications. By adjusting the porosity (e.g. Kelvin honeycomb, spiral Gyroid structure), we can customize the thermal conductivity, energy absorption, catalytic properties, etc., as if we were creating a tailor-made “metal coat” for different scenes.
Thermal management: putting a gas pedal on energy
In the heat storage tanks of solar power plants and the battery packs of electric cars, foam metals are quietly rewriting the rules of heat transfer. Traditional phase change materials (such as paraffin) can store heat, but due to poor thermal conductivity and “slow action”. The addition of foam metal, as if in the heat storage material paved a crisscross of “thermal conductivity highway” – the metal skeleton rapid heat absorption, pore in the phase change material efficient heat storage, the two collaborate, the thermal conductivity soared by more than 10 times. The study shows that the melting time of the foam metal composite phase change material with Gyroid structure is 31% shorter than that of the traditional structure, and the Primitive configuration is even more “simple and brutal” in terms of thermal conductivity efficiency. In the future, with the bionic pores accurately designed by 3D printing technology, this kind of material may become the “energy storage heart” in the era of green energy.
Into the teaching: the “magician” in the chemistry laboratory
In the chemistry classroom in secondary schools, foam metal is being transformed into an “experimental magic weapon”. A piece of foam nickel folded into the electrode will be able to extend the discharge time of the hydroxide fuel cell from 14 seconds to 67 seconds – only because the pores lock more gas; spiral curled foam copper-catalyzed ethanol oxidation, the reaction rate due to the contact area surge and doubled; even better, loaded titanium dioxide foam nickel in the ultraviolet light “Dance”, just 1 hour will be formaldehyde concentration from 0.7 mg/m³ down to 0.08 mg/m³, removal rate of nearly 90%. These experiments not only make abstract theories “visible and tangible”, but also plant the seeds of material innovation in the hearts of young students.
Noise reduction and safety: the “invisible guardian” in the city
In the hustle and bustle of the city, foam metal silently plays the role of “silent guardian”. Aluminum foam open-cell labyrinth-like pores swallow sound waves, become a concert hall, high-speed rail station noise reduction tool; and in the car bumper, aluminum foam such as “metal airbags” like energy-absorbing cushioning, collision absorbed energy than ordinary metal 30% higher. What’s more amazing is that this kind of material can even be used for building explosion-proof – the use of foam aluminum composite structure, successfully resisting the explosion shock wave, for the safety design to open up a new dimension.
The future is here: 3D printing reconfigures the material gene.
The pores of traditional foam metal are like naturally growing vines, random and uncontrollable. Today, laser additive manufacturing technology is breaking down this limitation. Scientists like “writing programs” like the design of Gyroid, IWP, and other biomimetic structures, so that the arrangement of pores such as honeycomb precision; combined with nano-particle filling technology, also create a “thermal conductivity + energy storage” dual-optimized super composite materials. Maybe shortly, we can customize a piece of pore structure with a cell phone APP, and print out foam metal in real time to fit different scenarios – from the heat insulation layer of spacecraft to the silent wall at home, everything is possible.
