The new foamed aluminum material is a new type of metal material that uses a specific process to fill bubbles into the aluminum melt, and uses a suitable method to retain the bubbles in the melt to form a gas-solid composite structure by cooling. According to different gas filling methods, the new foam aluminum material can be divided into closed-cell aluminum foam and open-cell aluminum foam. The performance of the new foam aluminum material mainly depends on its pore structure parameters such as porosity, pore size, through porosity, pore type, specific surface area, and its pore structure parameters mainly depend on the preparation process. Therefore, the preparation technology of foamed aluminum has become a research hotspot in the field of new materials.
There are many preparation processes for new foam aluminum materials. The mainstream commercial production of new foam aluminum materials mainly include: melt foaming method, melt blowing method and powder metallurgy method:
1. The preparation of new foamed aluminum materials by the melt foaming method is divided into multiple processes such as smelting, melt pretreatment, melt viscosity increasing, additive stirring, thermal insulation foaming, cooling, cutting, sheet post-treatment, storage, and packaging. Each process uses non-toxic and harmless metal materials, which can realize 100% recycling of production waste and recycled products.
2. The powder metallurgy method is to mix aluminum powder and foaming agent powder to obtain a preform with airtight structure through compression. The preform is heated to decompose the foaming agent to release gas, and the preform is forced to expand to obtain foamed aluminum. Compared with other methods, the powder metallurgy method has a wider range of available alloy components, which is conducive to improving the mechanical properties of the new foamed aluminum material, and it can also directly manufacture parts with complex shapes.
3. The melt blowing method is to first add SiC, Al2O3, etc. to the molten metal, and uniformly disperse to increase the viscosity of the melt, and then blow gas (such as nitrogen, inert gas, etc.) into the bottom of the melt, in the molten metal After forming a large number of pores, it cools and solidifies. The melt blowing method can realize the continuous preparation of new foamed aluminum materials, has simple equipment requirements, low cost, and controllable product porosity.