Processing and Characterization of a New Composite Metal Foam

Abstract

New closed cell composite metal foam has been processed using both casting and powder metallurgy (PM) techniques. The foam is comprised of steel hollow spheres packed into a dense arrangement, with the interstitial spaces between spheres occupied with a solid metal matrix. Using the casting technique, an aluminum alloy infiltrates the interstitial spaces between steel spheres. In the PM technique, steel spheres and steel powder are sintered to form a solid, closed cell structure. The measured densities of the Al-Fe composite foam, low carbon steel foam, and stainless steel foam are 2.4, 2.6, and 2.9 g/cm 3 with relative densities of 42, 34, and 37%, respectively. The composite metal foams composite materials developed in this study displayed superior compressive strength as compared to any other foam being produced with similar materials. The compressive strength of the cast Al-Fe foam averaged 67 MPa over a region of 10 to 50% strain, while the low carbon steel PM foam averaged 76 MPa over the same strain region, and the stainless steel PM foam averaged 136 MPa over the same region. Densification began at approximately 50% for the cast foam and ranged from 50 to 55% for the PM foams. The strength to density ratio of the product of both techniques exceeded twice that of foams processed using other techniques with similar materials.

Effect of Sphere Properties on Microstructure and Mechanical Performance of Cast Composite Metal Foams

“…Aluminum matrix CMF with steel hollow spheres has been studied extensively under monotonic compression and fatigue loading [1][2][3][4][5][6][7][8] and has shown mechanical properties unmatched with any other metal foam. As previously reported [3,4,7,8] aluminum-steel (Al-S) CMF contains hard and brittle intermetallic from the Al-Fe-Si ternary system dispersed through the matrix of the material.…”

“…The formation of intermetallics in the Al-Fe-Si system is a well-studied phenomena [9][10][11][12][13][14][15] and is due to the reciprocal diffusion of Fe and other alloying elements, like Cr and Ni, from the sphere wall into the Al-Si matrix, at the same time of diffusion of Al and Si from the matrix towards the sphere wall. Intermetallic formation in Al-S CMF influences the mechanical properties of the material and for that reason it has been widely studied [1][2][3][4][5][6][7][8]. In this study, the microstructure of Al-S CMF manufactured using spheres with different properties is investigated using SEM images along with EDS analysis.…”

“…The furnace used for heating up the spheres, mold and aluminum is a high temperature furnace from CM furnaces 3300 series (Bloomfield, NJ, USA) with molydisilicide heating elements capable of reaching 1700 °C. More details on the processing of composite metal foam via casting are presented elsewhere [1][2][3][4][5][6][7][8].…”

A Study on Dynamic Properties of Composite Metal Foams

“…Quasi-static compression testing shows a uniform deformation behavior without the presence of localized collapse bands, resulting in a high plateau strength in the range of 50-150 MPa depending on the material and processing methods (1). Composite metal foams have also been tested extensively under compression-compression fatigue, loading-unloading compression, and 4 point bending (2)(3)(4)(5)(6)(7)(8). However, their behavior at higher loading rates has never been tested.…”

A Review on Prodution of Aluminium Metal Foams

“…It's additionally shown to expertise fatigue degradation in each tension and compression. [16] aluminum metal Foam is taken into account as a material that's solid under low stress however it flows like a fluid beneath high stress. There's a precise vary of strain over that foams are elastic in nature and their deformation recoverable.…”