![cover image](https://wikiwandv2-19431.kxcdn.com/_next/image?url=https://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Aluminium_foam.jpg/640px-Aluminium_foam.jpg&w=640&q=50)
Metal foam
Porous material made from a metal / From Wikipedia, the free encyclopedia
In materials science, a metal foam is a material or structure consisting of a solid metal (frequently aluminium) with gas-filled pores comprising a large portion of the volume. The pores can be sealed (closed-cell foam) or interconnected (open-cell foam).[1] The defining characteristic of metal foams is a high porosity: typically only 5–25% of the volume is the base metal. The strength of the material is due to the square–cube law.
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/f/fc/Aluminium_foam.jpg/640px-Aluminium_foam.jpg)
![Thumb image](http://upload.wikimedia.org/wikipedia/commons/thumb/c/cd/Alv%C3%A9oles_4.jpg/320px-Alv%C3%A9oles_4.jpg)
Metal foams typically retain some physical properties of their base material. Foam made from non-flammable metal remains non-flammable and can generally be recycled as the base material. Its coefficient of thermal expansion is similar while thermal conductivity is likely reduced.[2]