Thermal decomposition behavior of novel gas-generating agent used for two steps foaming process of aluminum

The thermal decomposition behavior of a novel gas-generating agent(NGGA) used for two steps foaming process of aluminum was investigated, its kinetic and thermodynamic characteristics of decomposition reactions, and the potential reactions between the foaming gas and the melt were analyzed.The results show that the novel gas-generating agent has a wide decomposition temperature range and a slow decomposed rate, and its decomposition reactions during the melt are mainly controlled by chemical reaction process.The presence of an oxidizing gas released by NGGA, leads to reactions with the liquid melt, forming a continuous oxide film on the surface of the cell.The presence of the film has a significant effect on the foam stabilization, slowing down cell coalescence and growth.The NGGA exhibits a super performance with a low waste ratio in the former step and a high foaming efficiency in the later step during the two steps foaming process of aluminum.