Among the various materials used in the engineering field, metallic materials are gradually becoming important structural and functional materials due to their excellent properties in many aspects such as mechanics and processes. For conventional materials, holes are generally considered as structural defects, and they often become the center of crack formation and expansion, bringing adverse or even destructive effects on the material properties. However, when the number of holes in a material increases to a certain degree and is regularly distributed, the existence of these holes will make the material have some special properties, thus forming a new class of materials, which is called porous materials. The current artificial porous materials include porous plastics, porous ceramics, porous metals and so on. It is generally believed that when the porosity of porous materials is 40%98%, they can be called foam materials. Foam metal is a branch of foam material, and its structure has the following characteristics: larger pore size, higher porosity, lighter specific gravity, larger specific surface area, and the main component of the mesh skeleton is metal.

Aluminum foam is a widely used foam metal, which is composed of aluminum skeleton and pores, and is a new functional material developed in recent decades . As a structural material, it has the characteristics of light weight and high specific strength: as a functional material, it has various physical properties such as porous, vibration damping, damping, sound absorption, heat dissipation, impact energy absorption and electromagnetic shielding.
Although the application range of aluminum foam material is wide, but mainly focus on the application of its functional properties, and play the functional properties of aluminum foam is often at the expense of its mechanical properties. How to give play to the functional properties of aluminum foam and can maintain the structure of good mechanical properties has been a popular research direction, the current common solution is aluminum foam – steel composite materials — such as “sandwich” aluminum foam, is the strength of the metal for the surface layer, aluminum foam for the core layer of the sandwich panel structure. The main means of manufacturing aluminum foam sandwich panels, composite panels include bonding and welding.