Researchers at the St. Petersburg Polytechnic University have developed a method for the production of porous aluminum structures. Moreover, if necessary, porosity is created fragmentarily, in the necessary parts of these structures.
The areas of use of composite materials are constantly expanding, since the possibilities of monolithic structures are not limitless. For example, the fuselage of an aircraft must not only be strong, but also provide sound insulation and retain heat. Recently, more and more new technologies have appeared that combine several different properties in one metamaterial.
The technology developed at SPbPU is as follows. The metal plate is placed under the electric arc apparatus. There is also a nozzle through which gas is supplied. First, with the help of a moving electric arc, the metal is melted, while at the same time gas is supplied to the molten zone. As the arc moves, the metal begins to cool with the formation of pores. Their density and size is regulated by adjusting the parameters of the arc and gas jet.
The ability to form separate porous areas allows the production of metal structures with heat and sound insulation properties. At the same time, they are porous on the inside, and on the outside they will be reliably protected by a continuous layer of metal.
If the density of the metal is reduced to a minimum, then it can be used to create ultralight ships that will not sink even after receiving a hole.