Amorphous Mg-based metal foams with ductile hollow spheres

To date, high compressive ductility and energy absorption have been achieved in amorphous metal foams based on high-toughness Pdand Zr-based metallic glasses and are known to result from two extrinsic toughening mechanisms: bending of struts and shear band arrest by pores. We study here a syntactic amorphous metallic foam produced by infiltration of a bed of hollow crystalline iron spheres with a low-toughness Mg-based metallic glass Mg60Cu21Ag7Gd12 . After quenching to vitrify the matrix, this foam exhibits much higher compressive failure strain and energy absorption than the monolithic metallic glass, an improvement which is assigned to an intrinsic mechanism, i.e., composite toughening by the network of hollow ductile iron spheres. © 2007 American Institute of Physics. DOI: 10.1063/1.2756043