Compressive characteristics and low frequency damping of aluminium matrix syntactic foams

Al99.5 and AlSi12 matrix syntactic foams were produced by pressure infiltration of Globocer grade ceramic hollow spheres. The produced aluminium matrix syntactic foams (AMSFs) were investigated by compressive tests, dynamic mechanical analysis (DMA), finite element methods (DMA) and elasticity based analytical calculations. The aim of the investigations was (i) to map the compressive properties of the AMSFs, (ii) to determine and compare the effective Young's modulus of the AMSFs determined by compressive tests, DMA, FEM and analytical calculations and (iii) to determine the low frequency damping capability of the AMSFs. The compressive tests showed pronounced differences between the two matrix materials, characterized by higher compressive strength, compressive strain and absorbed mechanical energy in the case of AlSi12 matrix, however, the energy absorption efficiency due to the different failure mechanism of AMSFs (homogeneous densification in the case of Al99.5 and cleavage in the case of AlSi12 matrix, respectively). The DMA tests confirmed the effective Young's moduli values, measured by compression and proved higher damping capability in the case of AlSi12 matrix. FEM and analytical calculations also confirmed the measured effective Young's moduli within a reasonable error band.