• Exceptionally porous
• High compression capabilities coupled with excellent energy absorption characteristics
• Low thermal conductivity
• High endurance
• Aluminium, copper, nickel, and SS and their alloys are already valuable foam metals. Furthermore, foamed copper has a certain amount of growth space.
• Foamed aluminium and its alloys are lightweight and feature noise absorption, heat resistance, vibration abatement, impact energy absorption, and electromagnetic wave absorption properties.
• Foamed nickel exhibits significant air permeability and porosity because of its linked pore structure and good porosity; foamed nickel exhibits significant air permeability and porosity.
• Due to its high specific surface area and capillary force, it is primarily employed as a functional material in fluid filters, atomizers, catalysts, battery electrode plates, and heat exchangers.
Metal Foam Description and Specifications
Metal foam is a hexagonal structure made of solid metal; most often, it has a substantial volume proportion of gas-filled pores. The pores can be shut popularly as closed-cell foam, or they can link to form a network known as open-cell foam. Its high porosity distinguishes it; about 75-95% of the volume is made up of empty spaces. The density of foamed metal has a power-law connection with its strength; a 20% mass is more than twice as effective as a 10% dense one.
When the researchers add a foaming ingredient, granular titanium hydride, to liquid metal and allow it to cool, they obtain metal foam. The end product is a strong yet light material with 75-95% space. These are discerned by their extreme porosity, where the base metal accounts for just 5–25 percent of the volume. The square-cube rule is responsible for the material’s strength. It often maintains some of the source material’s physical qualities. The non-flammable composite metal foam stays non-flammable and, in most cases, may be repurposed as the inceptive material. It has a comparable coefficient of thermal expansion, but its thermal conductivity is likely lower.
Types of Metal Foams:
Open-cell Metal Foam
It is also known as a metal sponge. The material’s high cost often limits its usage to sophisticated technologies, aircraft, and manufacturing. In the chemical industry, fine-scale open-cell foams can be seen unassisted and are convenient as high-temperature filters. Their employment, however, allows for significant reductions in physical dimensions and manufacturing costs. The majority of these materials models make use of idealized and periodic structures, as well as averaged macroscopic features. A metal sponge has a relatively large surface area per unit weight, and catalysts, such as palladium black, platinum sponge, and spongy nickel, are frequently produced from it. Metals like osmium and palladium hydride are famous as “metal sponges,” although this phrase refers to their ability to attach to hydrogen rather than their physical structure.
Closed-cell Metal Foam
It is a novel structural-functional material with many great qualities. It may be separated into closed-cell metal foam and open-cell foam based on the pore structure. The former has holes that are not connected, and the latter has connected holes.
Method of Production
The formation of metallic melts occurs by producing gas bubbles in the liquid. Because of the high buoyancy forces in the high-density liquid, individual gas bubbles in the metallic melt strive to rise to the surface. The viscosity of the liquid metal must be increased to prevent this from happening. The metal foam panel has been accomplished by incorporating fine ceramic powders or alloying components into the melt to generate stabilizing particles. Injecting gas from an independent source into the liquid causes the ejection of gas that just absorbed into the liquid. Adding gas-releasing busting agents to the melt to cause in-situ gas production in the liquid
The following are three methods for foaming metallic melts:
Gas Injection Method
Hydro Aluminium in Norway and Cymat Aluminium Corporation in Canada employ foaming aluminium and aluminium alloys. To increase the density of the melt, magnesium oxide particles, silicon carbide, or aluminium oxide can be added.
To guarantee homogeneous particle dispersion throughout the melt, mixing processes must be constant. The molten material then foamed by introducing gases, specifically air, nitrogen, and argon, using revolving impellers or pulsating nozzles.
Blowing Agents method
A second way of directly producing foams is to introduce a blowing agent to the molten metal rather than pumping gas into it. Chemicals such as hydrides or carbonates bring gas into the melt.
The chemical decomposes and generates gas bubbles when annealed in liquid metal or semi-solid pellet. The resultant foam must be stable for the porous metals to have consistent pore size distribution and densities. Shinko Wire Company has used this process in Amagasaki, Japan, to manufacture foams. At 680°C (1256°F), 1.5 wt.% calcium metal is injected into an aluminium melt. The melt is well mixed, and the viscosity begins to rise due to the creation of calcium oxide, calcium aluminium oxide, or Al4Ca intermetallic. It contributes to the viscosity of the liquid metal.
When the viscosity reaches the appropriate level, titanium hydride is added as a blowing agent, causing hydrogen gas to release into the heated viscous liquid. The melt then continues to slowly and steadily expand, eventually filling the foamy vessel. The foaming must occur under steady pressure. When the container is cooled below the melting temperature of the composition, the liquid foam solidifies and remove from the mould for further processing.
Eutectic Solidification of Solid-Gas
Gasar, which means ‘gas-reinforced,’ refers to porous materials created through solid-gas eutectic solidification. Certain liquid metals are prevalent in creating eutectic systems with hydrogen gas. When one metallic composition melts in a hydrogen environment at up to 50 atm pressure, the resulting melt is homogenous and hydrogen-charged. The melt undergoes a eutectic transition on lowering the temperature, becoming a heterogeneous solid-gas system. A partition reaction will occur at a specific temperature if the solid-gas system has a eutectic concentration. As the melt solidifies, gas pores precipitate and become imprisoned in the metal. The pores that develop are mostly elongated and orientated in the position of solidification.
Metal Foam Applications
Heat exchangers such as cryogen tanks, compact electronics cooling, PCM heat exchangers, flow diffusion, energy absorption, CO2 Scrubbers, flame arrestors, and lightweight optics can profit from open-celled foam. These are often used in small heat exchangers to improve heat transmission while lowering pressure. It is also used as metal foam armour.
It is present in the frame or substructure of several automobiles. The frame has minimum metal, but it is stronger and more resistant to compression. It reduces the weight but increases strength in vital regions. It improves safety in the case of a collision or accident.
Crumple zones are not a new concept, but with the help of these foams, their efficacy increases. The ability to lose weight is also a great trait. When the train collides, the front crumples, with the metal foam structure bearing the shock and protecting the driver and passengers. Because of their poor thermal conductivity, these are appropriate for kitchen cookware as the “core” of handles. They are suitable for missile impact protection layers, aircraft and recovery parts, vehicle buffers, electrical and mechanical vibration dampening devices, and pulses. Electromagnetic wave shield, power supply, and so forth.
How to Use it?
These foams have various applications. Researchers can use them in their experiments. Make sure that researchers use all safety equipment while performing experiments.
• When working with sheet metal, always use heavy-duty gloves.
• To avoid inhaling sheet metal dust, wear a respirator or face mask.
• Never try to carry a large piece of sheet metal by oneself.
• After handling the sheet metal, thoroughly wash your hands with soap and water.
• Wear safety glasses to keep flying debris out of your eyes.
• Before operating power tools on sheet metal, be sure they are in good working order.
Why Choose Us?
Techinstro is eager to sell unique quality goods to our clients. We are leading manufacturers and suppliers of metal foams of all types, such as copper foam, nickel foam, aluminium meta foam, stainless steel foam etc. As a result, we understand market requirements and can meet them. Our products are of high quality and fit the requirements for both industrial and research applications. We provide product modification and personalization depending on our clients’ needs. Our items may be shipped anywhere in the world. We serve our clients with product assistance 24 hours a day, seven days a week. You will be delighted if you work with us.