Tensile Fatigue Properties of ZA27 Metallic Syntactic Foam

This study investigates the quasi-static and tensile fatigue properties of ZA27 metallic syntactic foam (MSF) containing expanded perlite particles. While the mechanical behavior of metallic syntactic foams has been widely studied under compressive loading, limited data are available for tensile and tensile fatigue performance. Cylindrical samples were fabricated using a counter-gravity infiltration casting method and subsequently subjected to thermal treatment to enhance their mechanical properties. Quasi-static tensile tests were performed to establish the relationship between ultimate tensile strength and density, revealing an increase in strength with higher density despite notable scatter caused by the stochastic foam structure. Fatigue tests under cyclic tensile loading at 60, 70, and 80 percent of the estimated ultimate tensile strength showed highly variable lifetimes, with most samples failing well below 500,000 cycles. Tensile fatigue performance was found to be similar to compressive fatigue. The results indicate that ZA27 syntactic foams are unsuitable for applications involving sustained or repeated tensile loading at high stress levels, and cyclic tensile loading should be limited to approximately 60 percent of the ultimate tensile strength or lower. Overall, the study highlights the critical influence of the foam geometry on both quasi-static and fatigue behavior and provides essential data for design and modeling of syntactic foam components under tensile loads.