Open cell lead foams: processing, microstructure, and mechanical properties

Abstract

Open cell lead foams with the porosities between 48 and 74 % were prepared by means of powder metallurgical and casting routes, using ammonium bicarbonate particles, silica beads, and sodium chloride salt particles as space holder. The resulting foam samples structure closely resembled open cell foam structure: each cell had few interconnections with neighboring cells. Small-sized lead (II) fluoride precipitates were microscopically observed in the interior of cells in the foam samples prepared using silica beads as space holder, resulting from the reaction between silica and hydrofluoric acid in the space holder dissolution step. The compression stress-strain curve of foam samples prepared by powder metallurgical route showed brittle deformation behavior following the initial elastic deformation region, while the foam samples prepared by casting route showed characteristic foam deformation behavior: cell edge crushing on the bent cell walls, and cell wall tearing. The collapse stresses, densification strains, and elastic moduli of the prepared foams were further fitted with scaling relations.

Polyolefinic nanocomposite foams: Review of microstructure-property relationships, applications, and processing considerations

“…58 The brittle behaviour of foams restricts their applications in many cases like cushioning, energy absorption. Embrittlement of foams manifests as in the form of crack development, 121 significantly lowering the mechanical as well as thermal performance. [121][122][123] Use of impact modifiers such as thermoplastic elastomers have been shown to reduce the embrittlement of PLA foams, 123 thereby broadening the lower-temperature applicability of the foams.…”

Experimental Investigation of Fluid Flow through Zinc Open-Cell Foams Produced by the Excess Salt Replication Process and Suitable as a Catalyst in Wastewater Treatment

“…Many researchers have confirmed that the manufacturing process strongly influences the foam's properties, which in turn has a direct impact on their applications, as reported by Dukhan [12], because of the relationship between intrinsic properties of the cells and the different thermal and hydrodynamic transports. Savaci et al [13] and Banhart [14] noted that the maximum porosities that can be achieved using space holders are limited to values below 80%. This research studied the transport of air in these ESR open-cell foams with porosities generally of 60%.…”

Temperature Effects on the Compressive Behaviors of Closed-Cell Copper Foams Prepared by Powder Metallurgy

“…As for the powder metallurgy (PM), the metal powder is sintered together with space holders, in which metal powder is used to form a metal matrix, while the space holders are employed to form the closed or open cells [ 22 ]. PM can be used to produce closed-cell and open-cell metal foams with a controllable cell shape and cell size, uniform distribution of the cells, and the necessary composition and properties of the metal matrix [ 23 ]. Recently, additive manufacturing is also employed, but only to fabricate open-cell foams by binder jetting [ 15 ] or a 3D-printed polymer mold [ 16 , 17 ], followed by pressureless sintering.…”