Microstructural examination and mechanical properties of replicated aluminium composite foams

Open-cell aluminium foams can be produced with the structural replication of dimensional accuracy from polymeric foam patterns through a pressure infiltration casting process. The strength of open-cell foam is much less than that of the closed-cell counterpart, and thereby subjects to mainly functional applications. An improvement in mechanical properties of the foams can be implemented with the addition of ceramic particles. In the present study, the composite foams were produced using AC3A alloy added with varying contents of SiC particles. The resultant foams have ceramic particles embedded in the alloy matrix and on the strut surface. Higher volume fraction of ceramic particles resulted in an increase in the compressive strength, energy absorption and microhardness of the foams. The improvement of these properties is due to the modification of the microstructure of the foams and the increased strength in the node and struts at which the ceramic particles reside.