Axial and radial compressive properties of alumina-aluminum matrix syntactic foam filled thin-walled tubes

The alumina-aluminum matrix syntactic foam filled thin-walled tubes (FFTs) were prepared by inserting aluminum matrix syntactic foams reinforced with alumina hollow spheres with three size ranges (1.0-1.5 mm, 1.5-2.0mm and 2.5-3.0 mm) into empty aluminum alloy tubes. For comparison with as cast samples, each type of syntactic foam underwent a T6 heat treatment. The FFTs and individual components were compressed in axial and radial directions. During axial compression, FFTs deformed by concertina mode, which was different from the diamond mode of tubes and the deformation characteristics of syntactic foams dominated by brittle fracture. The deformation mode of FFTs under radial compression was consistent with syntactic foams. The axial energy absorption was always greater than the radial energy absorption for FFTs and individual components under the same conditions. Regardless of the compression direction, the energy absorption of FFTs was higher than the sum of individual components. The energy absorption varied with hollow sphere size and heat treatment. The axial interaction effect between syntactic foam and tube in FFTs increased with deformation. The FFTs exhibited excellent specific energy absorption under axial and radial compression.