Effect of particle size and distribution of hollow spheres on the compressive behavior of aluminum matrix syntactic foams

Aluminum matrix syntactic foams (AMSFs) reinforced by Al2O3 hollow sphere (HS) with three different distributions of the particles were successfully produced by a self-developed counter-gravity infiltration casting technique. The effects of the size and distribution of particles on the quasi-static compressive behavior and failure mechanisms of the AMSFs was investigated. Microstructural images showed a clear interface between the fillers and matrix and no obvious shrinkage cavity was detected. The quasi-static compressive stress–strain curve of the AMSFs underwent three stages, namely linear-elastic, plateau, and then densification stages. The long plateau stage indicated that the AMSFs have excellent energy absorption capacity. The compressive strength and specific energy absorption capacity of the syntactic foam was lower when smaller particles were used and the compressive strength of bimodal AMSFs was much lower than that of monomodal AMSFs. The deformation of the AMSFs under compressive load, indicates that the distribution of the particles has an important influence on the failure mechanism of the AMSFs.