Preparation of Aluminum Foam Using a Novel Gas-Generating Agent

The thermal decomposition behavior of a novel gas-generating agent (NA) and its effect on the viscosity of aluminum melt were investigated, as well as the preparation technology of aluminum foam by using NA as foaming agent and viscosifier was presented. The results show that NA has a wide decomposition temperature range and a gentle decomposition rate, and NA can effectively increase the viscosity of aluminum melt, as a result, the dric-metal foaming agents such as TiH2 and ZrH2 can be replaced by NA and an extra viscosifier such as Ca is unnecessary during preparation process of aluminium foam by melt foaming method. The aluminum foam with porosity of 60%-85% can be prepared while the additive amount of fine NA powder as viscosifier is in the range from 0.6wt% to 1.0wt%, and the additive amount of coarse NA powder as foaming agent is in the range from 1.6wt% to 2.2wt%.