Compression and low-velocity impact behavior of aluminum syntactic foam

We report quasi-static compression and impact behavior of aluminum syntactic foams (ASF) produced by melt infiltration. Aluminum syntactic foams with relative density of 0.46 were produced using hollow alumina spheres (4.45 mm and 3.05 mm) randomly situated in a mold and two types of aluminum alloy (1100 and 6061). The impact behavior was investigated using an instrumented drop tower. We investigated the influence of the matrix alloy, the size of ceramic spheres, and the addition of a face sheet on the quasi-static compression and impact behavior of ASF. The 1100 Al ASF absorbed greater energy at higher velocities (penetration) than the 6061 Al alloy ASF, although at lower impact velocities, both ASF's absorbed the same amount of energy (equal-energy interval). The use of smaller microspheres did not increase the amount of energy absorbed compared to ASF's with larger microspheres and comparable relative density. The use of face sheets significantly increased the energy absorption capacity of the ASF's. Failure mechanisms are interpreted from impact load-displacement curves and examination of the impacted ASF plates. The properties of the ASF were compared to conventional aluminum foam and steel syntactic foams. The compression strength and energy absorption of the ASF were greater than that of conventional Al foams, but less than that of steel syntactic foam produced using the same hollow alumina spheres.