Effects of heating rate, holding temperature and holding time on porosity and pore morphology of aluminum foams fabricated by powder metallurgy process

We studied effects of heating rate, holding temperature and holding time on porosity and pore morphology of aluminum foams fabricated by powder metallurgy process. When the temperature of the specimen exceeds the melting point, the specimen starts foaming. The porosity of the molten specimen increases with increasing furnace temperature, and the porosity of the aluminum foam reaches about 80%. Pore morphology of aluminum foam becomes inhomogeneous because the cell face of the aluminum foam collapses during the passage of time. The heating rate hardly affects the maximum porosity. The furnace temperature as holding temperature are closely related with the porosity of aluminum foam. The porosity map of heating rate and elapsed time was obtained, and the aluminum foam with arbitrary porosity can be made using the porosity map.