Preparation Of Foamed Aluminum By Melt Foaming Technique

The foamed aluminum (FA) is a new type of multi-functional material that will have wide applications in the future. In this work, starting from the preparation of foamed aluminum material, some FA samples with basically controllable cellular structure and uniform distribution of cell were fabricated well by means of melt foaming technique (MFT). Moreover, the properties of static compression and electrical conductivity of the foamed samples were investigated, which can offer the basis for further practical application.In the process for preparation of FA, the decomposition property of the foaming agent as well as the controls to the temperature and rate for the decomposition of the material are vital to the structure and distribution of cells. In the study, titanium hydride is chosen as foaming agent. Then, titanium hydride usually decomposes at a lower temperature than melting point of aluminum. Aiming to the property, a surface-coated pretreatment to particles of titanium hydride was synthesized by a heterogeneous nucleation process. The experimental results show that the coated treatment makes titanium hydride gasifying at higher temperature and can delay the agent releasing hydrogen to some extent, which is beneficial to control cellular structure.Some facilities such as stirring device and crucibles were newly designed and fabricated in the laboratory. The influences of viscosity, stir and solidification of melting aluminum on preparation of foamed aluminum were studied. And some of initial parameters were improved and determined, such as the time and speed of stirring, the addition of titanium hydride, holding times and solidification mode on the processing of foamed aluminum. Finally, regular samples of foamed aluminum were manufactured, and the structure parameters of which are in the range of: densities 0.5g/cm~3～1.1g/cm~3, porosity 40%～85%, cell size 0.5mm～6mm.Static compression properties of foamed samples were tested with invariable strain rates on Material Test System (MTS). The results showed that intensities of the samples...