Al-Si Alloy Foam Prepared by Two Step Foaming Method

Two basic methods can be used to fabricate aluminum foam. One is powder metallurgy route which can provide the near net shape casting containing aluminum foam core, and the other is melt foaming route which can prepare large scale aluminum foam plate directly. To combine the advantages of above two methods, the precursor was obtained through melt foaming route and then baked in a furnace like that of powder metallurgy method in this investigation. The test results indicated that the SiC and TiH₂ particles after treatment in air could be dispersed in Al-Si matrix alloy melt and the precursors were obtained. The porosity and their pore diameter of the precursors decreased along with the temperature reducing as well as the magnesium or SiC particles adding. The density of Al-Si alloy foam decreased with the elevation of baking temperature and extension of heating time before collapse of foam block occurred. The foaming process parameters were seriously affected by the aluminum alloy composition.