Noticias

The advantages and disadvantages of foamed aluminum mainly depend on the pore structure parameters such as porosity, aperture, through-hole ratio, pore type and specific surface area, etc., and the pore structure parameters mainly depend on the preparation technology.
Therefore, the preparation technology of aluminum foam has become a research hotspot in the field of new materials.The preparation process of aluminum foam is described in detail below:
 
1. Solid metal sintering method:

Most of the foamed aluminium produced by this method has a through-hole structure, which is due to the fact that most of the solid phase methods connect the aluminium particles to each other through sintering, and the aluminium remains solid.
 

1.1 powder metallurgy foaming method

The process principle is to mix aluminum powder and foaming agent powder, after compression to get a prefabricated with air-tight structure, heating the prefabricated to make foaming agent decomposition and release gas, forcing the prefabricated to expand to foam aluminum.
Powder metallurgy foaming process process:
Mixing → pressing → sintering → cooling
Characteristics: first, compared with other methods, the available alloy composition is more extensive, which is beneficial to improve the mechanical properties of aluminum foam;Second, it can directly manufacture parts with complex shapes.The disadvantages of this method are the narrow range of technological parameters, high cost and limited size of aluminum foam.

1.2 powder sintering method
This method is often used to prepare copper foam.Because the dense oxide film on the surface of aluminum powder will prevent the particles from sintering together it is relatively difficult to prepare aluminum foam by powder sintering.At this time, the oxidation film can be destroyed by means of deformation, so that the particles can be more easily bonded or low-eutectic alloy can be formed when magnesium, copper and other elements are added and sintered at 595~ 625 degrees Celsius.
This method of production consists of three processes
Powder preparation → powder compression → powder sintering
Features: advantages are simple process, low cost, disadvantages are low porosity, low material strength,

1.3. Powder forming method

 It is the metal aluminum powder and foaming agent (hydrofluoric acid, aluminum hydroxide or orthophosphoric acid), additives and reaction of organic vehicle suspension, to stir it into the state of the bubble, and then put into a mould heating roasting, then plasma started to become sticky, and the effect of gas began to swell, end up with a certain strength of foam aluminum.If the slurry is directly injected into the polymer foam and the polymer material is pyrolyzed by heating, the open-hole foam material can be produced after sintering.
Powder → molding → roasting → aluminum foam
Characteristics: the aluminum foam is not strong and has cracks.