Effect of Aging Heat Treatment on Compressive Characteristics of Bimodal Aluminum Syntactic Foams Produced by Cold Chamber Die Casting

Recently, aluminum matrix syntactic foams (AMSFs) have become considerably popular due to their special physical and mechanical properties. Since these advanced engineering materials have a significant potential for different industrial applications, they can also be interpreted as alternatives to particle reinforced metal composites and traditional metal foams. This study, different from common laboratory scaled methods used in technical literature, emphasizes the possibility of AMSF fabrication using fully automated industrial-focused cold chamber die casting technology. In this context, 1–2 mm, 2–4 mm, and bimodal (50%vol) expanded glass (EG) reinforced syntactic foam samples were manufactured via a specially designed casting machine. Macro- and micro-observations (optical and SEM analyses) indicated that all fabricated syntactic samples exhibited perfect matrix/filler harmony using the proposed method. Density values of fabricated foams varied from 1.17 to 1.50 g/cm³ depending on EG size range. For the determination of mechanical properties, quasi-static compression tests were performed. Furthermore, T6 heat treatment was applied to some foam samples to comprehend the probable effects of the heat treatment on the compressive properties and fracture behaviors. The results showed that although there was a positive relationship between heat treatment and compressive properties of the fabricated foams, T6 treatment altered the failure styles of the samples by triggering matrix brittleness. Graphical abstract: [Figure not available: see fulltext.]