defects in aluminum foam with superfi ne open-cell structure

The infiltration casting process for producing aluminum foam includes three steps: preparing precursor using NaCl particles, infi ltrating molten aluminum and cleaning NaCl precursor. Defects occur during the preparation of aluminum foam with superfi ne open-cell structure, and infl uence the pore structure and performance of aluminum foam materials. The types of the defect and their forming mechanisms are analyzed in this paper. The defects include point defects and linear metal defects, and are caused by the defects in salt precursor and the insuffi cient infi ltration of molten aluminum into precursor. With the choice of proper precursor preparation method and infi ltration process parameters, the complete aluminum foam with superfi ne pores could be achieved.