The scaling of compression strength with porosity for aluminium foams was investigated. The Al 99.96, AlMg1Si0.6 and AlSi11Mg0.6 foams of various porosity, sample size with and without surface skin were tested in compression. It was observed that the compression strength of aluminium foams scales near the percolation threshold with Tf ≈ 1.9 -2.0 almost independently on the matrix alloy, sample size and presence of surface skin. The difference of the obtained values of Tf to the theoretical estimate of Tf = 2.64 ± 0.3 by Arbabi and Sahimi and to Ashby estimate of 1.5 was explained using an analogy with the Daoud and Coniglio approach to the scaling of the free energy of sol-gel transition. It leads to the finding that, there are two different universality classes for the critical exponent T f : when the stretching forces dominate T f = f = 2.1, respectively when bending forces prevail T f = .d = 2.64 seems to be valid. Another possibility is the validity of relation T f ≤ f which varies only according to the universality class of modulus of elasticity in foam.

The compression behaviour of closed cell aluminium foams (Al99.5, AlMg1Si0.6 and AlSi12 matrix alloys, TiH2 foaming agent) prepared by powder metallurgy was studied in the temperature range of 20-550 • C. It was observed that the temperature increase results in the decrease of the compression strength and energy absorption and increase of densification strain (plateau length) at constant density. The dependence of compression strength on foam density and temperature was successfully modelled using new proposed equation. The activation energy for compression of aluminium foams seems to be density dependent with a maximum at certain density range depending on foam composition. It was also found that the characteristic exponent T f for the compression strength of aluminium foams is temperature dependent variable. The strain at compression strength (deformation up to the macroscopic failure of foam) is nearly temperature independent or decreases at constant density depending on aluminium alloy matrix. The absorbed energy per unit volume of aluminium foams decreases with increasing temperature significantly due to the decrease in the value of plateau/compression strength at constant density.

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Abstract. Closed cell aluminium foam samples and panels with phase change material (PCM) infiltrated in vacuum were investigated. The utilization of PCMs in larger volumes is strongly limited because of its low thermal conductivity in liquid state. However, porous structure of aluminium foam allows to absorb or to dissipate very homogenously latent heat at almost constant temperature if PCMs with phase change at the temperature range between 4°C and 28 °C are used inside of foam. Therefore the degree of filling of closed cell aluminium foams with PCM material was investigated. It was shown that it is possible to fill sufficient amount of pores with PCM. Further, aluminium foam panels with PCM were tested for heating/cooling applications in buildings. It was confirmed, that such foam panels provide an excellent alternative for large built-in ceiling radiators for efficient heating or cooling of rooms using low potential energy resources. These features of foam panels allow significantly reduce energy consumption of heating/air conditioning systems of future zero energy buildings.