Mechanical and functional properties related to porous structure of recycled aluminium

Abstract

The present study describes mechanical and functional properties of open-cell metal foam associated with structural morphology and metal nature. Aluminium sponges were manufactured by melt infiltration of a pattern of NaCl with a recycled aluminium alloy using vacuum pressure followed by solidification, and finally the NaCl preform is removed by dissolution in water. The open-cell aluminium foams manufactured had a fully open interconnected porosity and a relative density around 0.33. Mechanical and functional properties associated with structural morphology and metal nature were evaluated. According with the test, several foam samples with pore size from 2.0 mm to 500 μm were studied. Uniaxial compression test was performed to determine the porous structure influence on plasticity and damage accumulation in the metal sponges. The standing wave tube method was used to determine the sound absorption coefficient in samples with 30mm diameter and 10-20mm thickness. To evaluate the permeability, pressure drop tests was carried out to have an understanding of the interaction of the fluid with the cell walls in the aluminium sponges. It is showed that sound absorption behaviour is affected by the pore size and an increase in strength with reduction in cell diameter was observed by uniaxial compression. The influence on the permeability of pore connectivity, pore size and sample thicknesses of the porous material have been reported. Several characteristics of the porous material have a notable impact on the energy absorption capacity, permeability and sound absorption behaviour without take into account the metal source to produce the sponge.