Grade, Density and Porosity
The pore size of the Recemat metalfoam is normally indicated by the pore range number, also called grade number. It relates to the range of pores per linear inch in the foam. For example: grade 1723 indicates 17 to23 pores/inch (ppi). The average pore size itself is also often indicated (Ø mm) to identify the cell structure of the foam.
Normally, the Nickel foams will be supplied with densities that fall in the range of 0.3 – 0.6 gr/cm3. The Nickel-Chromium foams are normally supplied in densities which range from about 0.5 – 1.2 gr/cm3. These densities are hardly related to the pore size of the foams.
The so called “relative density” indicates the mass ratio between the porous metal foam and the mass of the same volume of the basic solid material.
Porosity has been defined as the non-material part (%) of the foam. What is remarkable about Recemat® metal foam is that porosities as well as the densities of the metal foam are only in a very minor way related to the pore sizes.
This is an important quality of Recemat metalfoam, as most mechanical and physical properties depend on the density and the porosity of the metal foam, as well as the size of the pores and on the thickness of the trigonal structured struts of the metalfoam. These parameters govern all relations in an exciting way.
The “specific internal surface area” expressed as m2/m3 is strongly related to the grade and the poresizes.