Porous aluminium from ALUPOR – a permeable world of innovative possibilities

Porous aluminium – ALUPORTM – isn’t just a new way of using aluminium as a material. It is a new way of thinking aluminium and the possible ways of using it. ALUPORTM is an innovative material and the porous structure, the low weight and the advantageous price makes porous aluminium an obvious choice when:

  • Moulding EPS and thermoplastic.
  • Filtrating compressed air, natural gasses and liquids.
  • Reducing noise through silencers/mufflers.

In contradiction to traditional aluminium porous aluminium is not massive but has pours and is permeable. The pours are made with salt grains which make it possible to create pours in the exactly needed size by using salt grains corresponding to the needed pour size. It is possible to produce porous aluminium with a pour size of 100-5000 µm.

Endless benefits and possibilities

It is possible to use porous aluminium in numerous ways but no matter the use the material is characterized by many benefits which makes it an attractive choice compared to existing solutions on the market:

Sintret bronze
Sintret bronze

  • The porosity of ALUPORTM is 55-75 %. The density of aluminium is in advance very low, and it makes the material very light. Depending on the degree of porosity the weight of porous aluminium is 1-1.4 gram per cm3.


  • Porous aluminium is an obvious alternative to existing products as sintered bronze. Sintered bronze is bronze grains, which are connected to each other. Aluminium is significantly cheaper than bronze.

  • The porosity of porous aluminium is 55-75 %, and the porosity of sintered bronze is only 30-40 %.

  • It is possible to mould blocks which consist of both porous and massive aluminium. The combination of the materials makes it possible to combine the many benefits of porous aluminium with the high strength of massive aluminium, which is an excellent choice, when attachments are needed.

Producing ALUPORTM

Heated aluminium and salt grains are at first pressed together under pressure. When the mixture is hardened, the salt grains are removed. The grains leave prints from the salt grains in the aluminium block and creates a porous structure. The salt grains are washed out of the hardened aluminium item. It is important to rinse the entire item and remove the salt grains from the entire aluminium block. To make this possible the optimal thickness of the block is 50 mm, but it is possible to produce blocks with a thickness of 440 mm and still achieve an excellent result.

The porous structure of Alupor™ is formed by dissolving of salt from aluminium matrix
The porous structure of Alupor™ is formed by dissolving of salt from aluminium matrix

Optimizing the productivity with forms made of porous aluminum

Expanded Polystyrene Foam (EPS) is often moulded in aluminium forms. Gas is used throughout the process, and it needs to be led away from the EPS material and the tool. The moulding form has holes, which transport the gas away from the moulding chamber. The transport of gas can be a limiting factor since it slows down the process and reduce the possibilities of the tool. By using an aluminium form made of porous aluminium instead of massive aluminium, it is possible to increase both the productivity and functionality.


Inserts for mould
Inserts for mould
Alupor premachined Mould
Alupor premachined Mould

The porous structure leads the gasses away, and it will not be necessary to make holes and process the moulding form. This gives new production and design possibilities and makes it possible to produce EPS pieces with a high level of details. Since you can choose your needed pour size we are offering a material, which is suited each need and gives you the possibility to mould a precise and sharp result.

The density of porous aluminium is very low. The low density requires only little energy when heating up the material. This is very advantageous, when porous aluminium is used for tools since the heating of the tool takes very little energy compared to heating of tools made of massive aluminium. The open structure of porous aluminium enables the moulded item to cool down faster as more air enters the tool. Thus more pieces are produced faster and the production increases efficiently.

Filters and mufflers made of ALUPORTM

The open structure of porous aluminium makes the material permeable. If high effectivity and low costs are needed, filters and mufflers made of ALUPORTM are the perfect choice. The structure of the material is characterized by having a perforated connection between the pours, giving porous aluminium more permeability and a high filtration degree. This makes the material particularly suited for filtration of air, gasses, liquids and others. At the same time, the open structure lets pressure pass through the material without a lot of resistance and this results in a relatively low flow resistance. This can be very advantageous, when the filters are used in compressors, vacuum cleaners and other machines where it’s important to obtain a high, effective pressure. The size of the pours decides the porosity of the aluminium. Different porosities result in different flow resistances, and it makes it possible to calculate the precise flow resistance from the chosen pour size. With ALUPORTM we give you the possibility to choose pour size based on desired effect and the highest accepted flow resistance.

Machinable • Superior ventilation • Various structures
Machinable • Superior ventilation • Various structures

The permeability of porous aluminium also gives the material high impact absorption. When waves of sounds, air, water and other mediums reach the porous aluminium the open structure absorbs the frequencies of the waves. The degree of the impact absorption depends on the porosity of the material. This makes mufflers made of porous aluminium very effective and give us the opportunity to tailor solutions especially suited your needs.

Would you like to know more about the ALUPORTM products and the possibilities with this innovative and multi applicable material? Do not hesitate to contact us!



Technical Information:

ALUPOR™ VS Porous metals

Property Sintered bronze  CYMAT


Aluminium foam


Porosity, % 30-40 80-98 80-98 55-75
Porosity type open-cell closed-cell open-cell open-cell
Average pore size, μm 3-250 200-50000 200-5000 100-5000
Min pore diameter, μm 5   42278 25-35 40-60
Darcy permeability,  m2 0.4×10-11 - 25×10-11  - (1.0-4.4) ×10-5 1×10-12- 2000×10-12
Compressive strength, MPa 60-200 5 2.5 35-109
Tensile strength, MPa 45-150 3.5 1.24 10-30
Normal elasticity module, GPa 150-200 1.3 0.15 1.0-4.0
Heat conductivity, W(m·K) 4.68  2-15 5.8

35  alloy

50 pure Al

Electric conductivity, Sm/m 1×106 - 5×106 1.2×106 1.4×106 3.55-×106 -4.78×106 
Heat expansion coefficient, 1/К 18×106 23.6×106 23.6×106 23.6×106


Structure properties

Property Material type (graded by main pore size range), μm
100-200 140-315 200-400 315-630 630-1000 1000-1600 1600-3000
Porosity, % 55±5
Filtration degree, µm 5 10-15 25-35 40-60 80-110 120-150 200-250
Specific surface m2/m3 18300 12500 9700 6300 4600 2800 1400
Darcy permeability , m2 0.6×10-11 0.7×10-11 0.9×10-11 3.1×10-11 7.5×10-11 15.8×10-11 23.1×10-11
Forchheimer permeability (ki), m 1.5×10-5 3.3×10-5 3.5×10-5 3.6×10-5 3.8×10-5 4.2×10-5 19.0×10-5

Specific quantity of pores 

on the surface, pcs./m2

26.6×106 11.6×106 6.7×106 2.6×106 1.0×106 1.0×106 1.0×106

Specific quantity of air necks

on the surface, pcs./m2

83.7×106 36.4×106 20.9×106 8.4×106 4.3×106 1.5×106 0.35×106

Mechanical properties

Property Material type (graded by main pore size range), μm
100-200 140-315 200-400 315-630 630-1000 1000-1600 1600-3000
Ultimate compressive strength, MPa 118 105 59 58 49 37 32
Yield point at compression, MPa 44 39 26 24 20 21 20
Ultimate tensile strength, MPa 33 29 16 16.5 14 12 8
Yield point at tensile, MPa 30 26 14 16 13 13 7
Ultimate shear stress, MPa 41 36 34 30 25 26 -
Young's modulus, GPa 3.5 3.1 2 1.9 1.7 1.7 1.6
Elongation, % 0.25 0.29 0.38 0.27 0.32 0.3 0.12

Physical properties

Property Material type (graded by main pore size range), μm
100-200 140-315 200-400 315-630 630-1000 1000-1600 1600-3000
Heat conductivity, W/(m·K) 30-50
Heat capacity at vacuum, J/(kg·K) 380-420
Electrical conductivity Sm/m 4.8-7.2×106