Fracture behavior of metal foam made of recycled MMC by the melt route

Metal foam was made from recycled MMC precursor by the melt route. The original starting material was an Al-9Si alloy containing 20vol% of Sic particles (10 mu m), which are used to stabilize the foam during the foaming process. The starting material has been used to make foam parts from which the residue was recycled and refoamed. During the (re)foaming process Fe is present in the melt. During solidification of the foam, beta-AlSiFe plates are formed with the surplus of Si and Al present in the alloy. These plates run through the entire thickness of the cell wall (40-50 mu m) and their length ranges between 50 and 200 mu m. During in-situ tensile tests fracture initiates in the beta-AlFeSi plates and propagates through other beta-AlFeSi plates leading to brittle fracture of the cell walls.