Synthesis and Quasi-Static Compressive Properties of Mg-AZ91D-Al2O3 Syntactic Foams

Abstract

Magnesium alloys have considerably lower density than the aluminum alloy matrices that are typically used in syntactic foams, allowing for greater specific energy absorption. Despite the potential advantages, few studies have reported the properties of magnesium alloy matrix syntactic foams. In this work, Al2O3 hollow particles of three different size ranges, 0.106–0.212 mm, 0.212–0.425 mm, and 0.425–0.500 mm were encapsulated in Mg-AZ91D by a sub-atmospheric pressure infiltration technique. It is shown that the peak strength, plateau strength and toughness of the foam increases with increasing hollow sphere wall thickness to diameter (t/D) ratio. Since t/D was found to increase with decreasing hollow sphere diameter, the foams produced with smaller spheres showed improved performance—specifically, higher energy absorption per unit weight. These foams show better performance than other metallic foams on a specific property basis.

Functionally-Graded Metallic Syntactic Foams Produced via Particle Pre-Compaction

“…One recent development is a focus on metallic syntactic foams (MSFs). In these materials, porosity is introduced by combining hollow [5][6][7][8] or inexpensive porous particles [9][10][11][12][13] with a metallic matrix. This approach enables the control of pore geometry and negates the need for costly foaming agents and manufacturing equipment [14].…”

Enhancing the Ignition, Hardness and Compressive Response of Magnesium by Reinforcing with Hollow Glass Microballoons

“…Recent review articles have detailed the synthesis methods, microstructures, mechanical properties and applications of Mg, Al, and Ti matrix syntactic foams [ 7 , 8 ]. Engineered hollow spheres of SiC and Al 2 O 3 [ 9 , 10 ], inexpensive fly ash cenospheres, and hollow glass microballoons (GMB) [ 11 , 12 , 13 , 14 , 15 ] have been used as fillers in developing these syntactic foams.…”

Microstructure and compressive properties of aluminum matrix syntactic foams containing Al2O3 hollow particles

“…Therefore, the wall thickness may be different for each Al 2 O 3 hollow particles. For these reasons, it may be difficult to quantify the ratio of wall thickness (t) to diameter (D) [45]. By considering the geometry of the sphere and the average density of the sphere, one method to determine the t/D ratio is derived, as shown in Eq.…”

“…By considering the geometry of the sphere and the average density of the sphere, one method to determine the t/D ratio is derived, as shown in Eq. (1) [45]:…”