Abstract:
Aluminum Foam Interpenetrating Phase Composites (IPCs) are now a research focus with broad applications. However, conventional aluminum foam IPCs face a strength-ductility trade-off. To overcome this limitation, this study develops a novel Aluminum Foam-Polyurethane-Epoxy Interpenetrating Phase Composites (APEC) with layered Polyurethane (PU)and Epoxy resin (EP) filling in an open-cell Aluminum Foam (AF) skeleton. Quasi-static monotonic compression tests are performed on APEC and traditional aluminum foam IPCs (AF-PU and AF-EP), and their stress-strain behavior and energy absorption properties are systematically compared. Test results show that APEC combines the hyperelasticity of PU with the high strength of EP, achieving a simultaneous improvement in strength, in ductility and, in energy absorption. The yield strength and plateau stress reach 33.3 MPa and 42.6 MPa, about 175% higher than those of AF-PU. The densification strain of APEC reaches0.645, approximately 67% higher than that of AF-EP. The energy absorption up to the densification and to the specific energy absorption of APEC reach 24.2 MJ/m
3 and 14.7 J/g, about 194% higher than those of AF-PU, and it maintains a high ideal energy absorption efficiency of about 0.85 over a wide strain range of 0.15-0.6. Furthermore, APEC exhibits strong orthotropy, with direction-dependent mechanical and energy-absorption properties, making it suitable for impact protection, for structural safety, and for bridge anti-collision applications. This study provides a useful reference for future researches and applications of interpenetrating phase composites.