Effect of aging heat treatment on mechanical properties of expanded glass reinforced syntactic metal foam

Metal matrix syntactic foams (MMSFs) are advanced engineering materials, and their properties like low density, high compression strength, good ductility, and excellent energy absorption capability make them considerably attractive for many industrial applications nowadays. In this research paper, a new production method named sandwich infiltration casting was used to manufacture metal syntactic foams, including Al 7075 matrix and expanded glass (EG) fillers with 2-4 mm diameter. As a result of the porous structure of EG particles, density values of the fabricated aluminum matrix syntactic foams (AMSFs) changed between 1.39 and 1.47 g cm⁻³. Micro observations showed that there was perfect harmony between the matrix and EG particles as a consequence of effective process optimization and adequate wettability of the EG spheres. In addition, T6 heat treatment was applied to specific samples to analyze the possible effect of aging on the mechanical properties. The results indicated that expanded glass had great potential for syntactic foam applications compared to the other filler types utilized in previous efforts. Moreover, it was apparent that there was a favorable relationship between the heat treatment and compressive properties (compression strength, plateau strength, and energy absorption ability) of the fabricated foams.