Manufacture of Aluminum Closed-cell Foam by ARB process using CaCO3 as the blowing agent

Metal porous foams have been eliciting much interest in recent years due to their high capacity of energy absorption. The characteristics of the pores in these materials play an important role on their energy absorption capability and other properties. This study reports the fabrication of aluminum closed-cell foams by accumulative roll-bonding (ARB) technique using calcium carbonate (CaCO3) as the blowing agent. Calcium carbonate is an inexpensive material and imparts relatively high porosity to the produced foam. The effects of heating rate foaming temperature and time on porosity have been investigated. The results show that increasing the foaming temperature and time results in improvements in the foaming process. It is also shown that the heating rate does not affect the porosity. The shape and structure of pores are spherical and regular with CaCO3 as blowing agent. With TiH2 blowing agent the sample should be heated up abruptly from decomposition temperature of TiH2 to foaming temperatures in order to produce high porosity foam. It is found that increasing the numbers of accumulative rolling cycle causes uniform distribution of calcium carbonate powder and increases porosity in the final foam by up to 55%.