Effect of Alloy Contents on the Compression Performances of Porous Aluminum by Melt Route

In this research, for the closed cell Al-Zn-Mg alloy foams which are fabricated by adding foaming agent to molten aluminum (direct aluminum foaming in melt), the effect of alloy contents and heat-treatment on the uniaxial static compression strength was examined. As a result, it was possible to achieve high compression strength by an increase in hardness and using appropriate alloy contents. The plateau region becomes longer, because the cell wall of Al-Zn-Mg alloy foams tends to incur brittle fracture by alloying. However, Al-Zn-Mg alloy foam with excessive alloy contents exhibits lower compression strength. There were few hardness improvements caused by heat treatment. Heat treatment did not cause improvement of compression strength. When the compression strength of Al foams is shown in relation to density and plateau stress, plateau stress of Al-10.0%Zn-0.3%Mg (mass%) alloy foam was about 1.7 times, and Al-10.0%Zn-1.0%Mg alloy foam was about 2 times higher than Al foam in density.