Effect of Green Body Formation by Single and Double Action Pressing on the Mechanical Properties of Al Foams

In the present study, aluminum foams with a relative density of 0.38 were fabricated through powder metallurgy route by using carbamides as space holders. The effect of using double and single action die pressing methods to produce green compacts, were studied on the mechanical and energy absorption capacity of the fabricated foams. Carbamide space holders were removed by being leached in water, whereafter the samples were sintered at 640oC for 2 hours in air. Mechanical properties and energy absorption capability of the fabricated foam samples were evaluated by the means of compression test. The results proved that double action die pressing method can significantly improve mechanical properties and energy absorption capacity of the fabricated foam by creating more uniform density distribution in foam structure. Therefore, for foams with a relative density of 0.38, using double action die pressing process caused nearly 95 % increase in plateau stress and more than 24% improvement in energy absorption ability for the fabricated foam.