Production of open-cell Al composite foams by direct casting with silica-gel beads

Abstract

Open-cell Al composite foams, with the addition of Al2O3 particles, have been successfully produced, using direct casting technique of space holder materials. The amorphous silica-gel (SiO2) beads of 3 mm were employed as a space holder. The ADC12 cast Al alloy was added with 1-5 wt.% Al2O3 particles, prior to casting process. The infiltration of molten Al composites was performed at 750°C for 30 min with a pressure assistance. Elimination of silica-gel beads was achieved, using the solution of hydrofluoric (HF) acid for 10 h, resulting in open-cell foams with a porous structure, replicated to the morphology of silica-gel beads. However, it was found that the foam structure was also slightly damaged during the removal process of silica-gel beads.© 2017 Elsevier Ltd. All rights reserved.Selection and/or Peer-review under responsibility of The 10th Thailand International Metallurgy Conference.