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TopSynthesis Of Al-Mmc Foam
The material under investigation is closed cell aluminium foam, manufactured through Stir-Casting route in the laboratory, using aluminium alloy (LM6: consisting of 0.1% Cu, 0.1% Mg, 0.13% Si, 0.6% Fe, 0.5% Mn, and trace amount of Zn, Pb, Sn and rest Al). The achieved high viscosity, due to addition of SiC in the melt, allows liquid Aluminium to be stable at a temperature of TiH2-decomposition (465°C) (Sutradhar, 2015; Haidar & Ansary, 2016).
2 - 3% foaming agent (Titanium Hydride) is added to the mold. TiH2 begins to decompose into Ti and gaseous H2 when heated above about 465°C. Thus, large volumes of hydrogen gas are rapidly produced, creating bubbles that leads to a closed cell foam. It is necessary to stir the mold with constant speed for good foaming with homogeneous arrangement of cells.
A major hindrance of production of this future material is the current cost of production. The current work provides a means to produce aluminium foam of acceptable properties with less use of metal hydrides (Haidar, Mandal, & Sutradhar, 2015). The cost of the material is reduced by addition of a secondary blowing agent i.e. CaCO3, which reduced the requirements of costly metal hydrides. Thus, instead of adding 2% - 3% TiH2, a dual foaming agent, 2% - 5% CaCO3 and 0.5% – 1.0% TiH2 are added separately which produces even better result.