Fabrication of composite material using alumina agglomerated sludge and aluminum powder by spark plasma sintering

The composite material was fabricated using alumina sludge, industry waste, and aluminum powder by spark plasma sintering (SPS). Sludge of industry waste was treated to change the a alumina crystal structure at temperature 1573 K for 2 hours. The bending strength of the composite materials was investigated by changing the volume fraction of sludge 0-6% and forming conditions. As a result, it was found that the sludge content mainly affected on the bending strength. The bending strength showed the highest value at 2% sludge content. From the observation of crack propagation using optical microscope, it became clear that the sludge existed as agglomerated powder in the composite material, and this sludge prevented the crack to propagate.