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

Abstract

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.