A356 alloy foaming by titanium hydride

In this study the parameters which affecting on foaming process of aluminum A356 for preparing of light products are investigated. Titanium hydride (TiH2) powder as a foaming agent (0.5 to 2.5 wt %) added to the aluminum melt. This is focused on thermal decomposition behavior of titanium hydride on the melt foaming during casting and unidirectional solidification of A356 alloy. Therefore, the effects of heating temperature, stirring time and TiH2 wt %, on percentage of porosity have been investigated. It was found that with the optimum torque of 0.35 Nm for the melt and TiH2 addition of 1.0–1.5 wt %, remarkably foaming efficiency could be achieved. Foamed A356 cross sections were microscopically characterized by Scanning Electron Microscopy corresponding to different TiH2 contents. The optimum amount of titanium hydride content induces uniformity in porosity cell structure distribution in the whole cross section of the foamed aluminum. Medium thickness of thin cell wall is near to 20 μm which is easily broken or disrupted.