Fabrication of aluminium foam through pressure assisted high frequency induction heated sintering dissolution process: an experimental observation

A process based on powder metallurgy approach was developed to produce open celled
aluminium foam. In the preparation of foam specimens, the Al powder and the NaCl (leaching
agent) were dry mixed together in order to prepare a homogeneous mixture. The blended mixture
was then subjected to pressure assisted sintering in which a pressure beyond atmospheric level
is externally applied to the specimen during high frequency induction heated sintering. The
embedded leaching agent was then dissolved in order to leave behind an open celled Al with the
same chemical composition as that of the original Al powder. The final material is highly porous
and has an interconnected porosity network. The structure of the resulting material has three
levels of porosity (i.e. main cells, windows and microporosity). The X-ray diffraction analysis
shows that, as the content of NaCl is increased to the volume fraction of 60%, no traces of NaCl
presents in the foam.