Influence of mold temperature on the compressive properties of Al-foam fabricated through vacuum casting.

For making an aluminium (Al) foam through the melting route, a pressurized process such as vacuum casting is considered a potential technique due to its feasibility to flow the melt through a narrow area in a short time. In this work, cylindrical Al foam was cast using spherical silica gel (SiO2) particles as the space holder. After the SiO2 particles were loaded inside the cavity, the mold was then pre-heated under different temperatures (80, 100, and 120 °C). Afterward, Al melt was poured onto the basin and subsequently filled the cavity under the vacuum pressure of -20 inHg and the foam was released after it was solidified. Before moving into the compressive test, the SiO2 particles were dissolved into the solvent and weighed to measure the porosity. Although showing the higher porosity, the compressive test revealed that the lower mold temperature resulted in higher maximum compressive strength and elastic modulus of 18.38 MPa and 1.55 GPa at the strain limit of 60%. It implied that the microstructure played an important role to characterize the compressive properties of the open-cell Al foam. [ABSTRACT FROM AUTHOR]