A study on processing of a composite metal foam via casting

The research sited in this paper involves the development of a new closed cell composite metal foam using gravity casting techniques. The foam is comprised of steel hollow spheres packed into a random dense arrangement, with the interstitial space between spheres infiltrated with a casting aluminum alloy. The measured density of the material is 2.4 g/cm3, with a relative density of 41.5%. The composite foam developed in this study displayed superior compressive strength and energy absorption capacity. The compressive strength averaged 67 MPa over a region of 10–50% strain, densification began at approximately 50% strain, and the energy absorption at 50% strain is 30 MJ/m3. Scanning electron microscopy (SEM)–energy dispersive X-ray spectroscopy (EDX) compositional analysis affirmed the presence of expected phases in the hollow spheres and aluminum matrix. This novel material has promising applications in the aerospace, automotive, and biomedical industries.