Compressive behaviour of open-cell Al–Si alloy foam produced by infiltration casting

Abstract

Open-cell Al–Si alloy foams with different densities were manufactured by vacuum infiltration. The foam with smaller NaCl as space holders showed a mixed scaffold structure consisting of abundant struts and cell walls. It was also found that the open-cell Al–Si alloy foam showed various defects containing micropores, microcracks and missing cell walls. The compression results indicated that the open-cell Al–Si alloy foams exhibited smoother stress–strain behaviour and higher compressive strength than that of previous studies, despite a larger number of defects in brittle Al–Si matrix. The successive occurrences of multiple deformation bands owing to the mixed structure and various defects were responsible for the smooth compression stress–strain behaviour.

Preparation and Compression Behavior of High Porosity, Microporous Open-Cell Al Foam Using Supergravity Infiltration Method

“…Therefore, the plateau stress (σpl) is used to represent the plastic collapse. On the other hand, a small number of cell walls and struts form a mixed strut structure, resulting in a higher compressive strength at the same density compared to the Gibson-Ashby model [14]. Figure 10b illustrates the relationship between the relative density and plateau stress of Al foam in both the current study and other studies [13,[21][22][23].…”

“…Therefore, the plateau stress ( σ pl ) is used to represent the plastic collapse. On the other hand, a small number of cell walls and struts form a mixed strut structure, resulting in a higher compressive strength at the same density compared to the Gibson–Ashby model [ 14 ].…”

“…Bhasker Soni et al [ 13 ] prepared a 6061 Al alloy foam with porosity ranging from 0.5 to 0.75 via the pressure infiltration method, and investigated both the porosity and mechanical properties of the samples with different porosities. Xia et al [ 14 ] prepared open-cell Al foam with a porosity of 0.65–0.77 and a pore size of 0.15 mm–0.6 mm using vacuum infiltration with NaCl as a preform. However, higher porosity microporous Al foam is less reported due to the increased difficulty of preparation as porosity rises and pore size decreases.…”