A comparison of composite metal foam's properties and other comparable metal foams

New closed cell composite metal foams are processed using casting and powder metallurgy (PM) techniques. The foam is comprised of steel hollow spheres packed into a random loose arrangement, with the interstitial spaces between spheres occupied with a solid metallic matrix. The characterization of composite metal foams was carried out using monotonic compression, compression-compression fatigue, loading-unloading compression, micro-hardness and nano-hardness testing. The microstructure of the composite metal foams was studied using optical, scanning electron microscopy imaging and electron dispersive spectroscopy. The composite metal foams displayed superior (5-20 times higher) compressive strengths, reported as 105 MPa for cast foams and 127 MPa for PM foams, and much higher energy absorbing capability as compared to other metal foams being produced with similar materials through other technologies.