Study on fabrication and foaming mechanism of Mg foam using CaCO_3 as blowing agent

摘要

Using CaCO_3 as blowing agent and via melt foaming method, Mg foams with closed-cells have been fabricated successfully. It has been proved that the blowing gas to foam melted Mg is not CO_2 but CO, which is released from the liquid-solid reaction between Mg and CaCO_3. The releasing temperature of CO is more than 100 deg C lower than the decomposition temperature of CaCO_3, which leads to melted Mg being foamed much more easily and the foaming process can be accomplished in a temperature range of 665-750 deg C.