Acoustic emissions analysis of damage in amorphous and crystalline metal foams
نویسنده
چکیده
Acoustic emission methods are used to investigate the nature and evolution of microfracture damage during uniaxial compression of ductile amorphous and brittle crystalline metal foams made from a commercial Zr-based bulk metallic glass, and to compare this behavior against that of aluminum-based foam of similar structure. For the amorphous foam, acoustic activity reveals evolution of the damage process from diffuse to localized damage through the foam stress plateau region, and reversion back towards diffuse damage in the foam densification region. Accommodation of microfracture by surrounding ductile struts, and significant point contact formation, permit high average compressive strains of ca. 80% in the amorphous foam without macroscopic failure. q 2006 Elsevier Ltd. All rights reserved.
منابع مشابه
Processing and Properties of Advanced Metallic Foams A DISSERTATION
Processing and Properties of Advanced Metallic Foams Alan Harold Brothers Since the development of the first aluminum foams in the middle of the 20th century [178], great advances have been made in the processing and fundamental understanding of metallic foams. As a result of these advances, metallic foams are now penetrating a number of applications where their unique suite of properties makes...
متن کاملAmorphous metal foams
As recently demonstrated, amorphous metal foams are highly ductile in compression, and thus offer attractive compromises in mechanical and physical properties between crystalline metallic and ceramic foams. Challenges associated with fabrication of amorphous metal foams are critically assessed in the context of current and future processing methods, and conclusions are drawn regarding the prope...
متن کاملAmorphous 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...
متن کاملCorrelation Between the Acoustic and Cell Morphology of Polyurethane/Silica Nanocomposite Foams: Effect of Various Proportions of Silica at Low Frequency Region
Introduction: Reducing noise pollution has become an essential issue due to the increase in public concern and also social demands for a better lifestyle. Using sound absorption materials is a preferred method to reduce the noise pollution. Undesirable properties of pure polyurethane such as poor absorption of mechanical energy in narrow frequency ranges can be improved by providing polymeric n...
متن کاملEffect of non-acoustic properties on the sound absorption of polyurethane foams
In this paper the influence of non-acoustic properties on the sound absorption coefficient of polyurethane foams as a porous medium is investigated. Biot’s equations with transfer matrix method, as the solution approach are employed to evaluate the sound absorption coefficient of selected polyurethane foams. The major issue is the dependency of non-acoustic properties on each other which makes ...
متن کامل