Characteristic compressive properties of hybrid metal matrix syntactic foams

Hybrid metal matrix syntactic foams (hybrid MMSFs) are particle reinforced composites in which the reinforcement is the combination of more than one grade of hollow spheres. The difference between the spheres can be in their chemical composition, dimension, physical properties etc. In this study AlSi12 matrix hybrid MMSFs with monomodal Globocer (Al2O3 and SiO2 based ceramic) and Globomet (pure Fe) reinforcements were produced by pressure infiltration. The investigation parameters were the ratio of the hollow sphere grades and the aspect ratio of the specimens. Microstructural investigations showed almost perfect infiltration and favourable interface layer, while quasi-static compression tests showed that the composition of the reinforcement and the aspect ratio of the specimens have determinative effect on the characteristic properties (compressive and flow strength, fracture strain, stiffness and absorbed energy). This nature of the MMSFs ensures the possibility to tailor their properties in order to optimise them for a given application.