Preparation Of Aluminum Foam With Large Size And Composite Structure

As a new type of functional materials containing holes and hole edges,aluminum foam is applied in various fields. And its particular structure determines that the aluminum foam can be used in the military, buildings,vehicles and other fields relating to national economy and livelihood. The sandwich structure produced through aluminum foaming has both the ductility properties of foamed aluminum and the mechanical properties of metal plate material. The study about foam material has decades of history, and many preparation methods have been developed. The mixed powder compaction way(commonly known as the PCM method) in the preparation of aluminum foam sandwich. With different shapes and complicated pore structure and excellent performance has been widely used.This paper contains four parts based on the PCM method:(1) the effects of foaming behavior on foaming agents and the materials;(2) the influence of packing method, foaming time and heating temperature on the foaming behavior in the circular tube;(3) the research of preparing sandwich strcture by using copper brazing agent. The filling behaviour of large sized special-shaped mould.The result indicated that:(1) Different materials, different heating rates and different preform foaming agent had great influence on the mold filling and pore structure. The time of reaching platform, length of area and temperature of reaching the maximum expansion point with Zr H2 as foam agent are more than that adding Ti H2 as foam agent. The aluminum silicate mixed powder as matrix metal powder prefabricated body heated at 780?, 800? and 820? respectively was compared with pure Al powder and the results show that aluminum silicon powder mixture as foam effect have better pore structure.(2)The packing way, foaming time, foaming temperature had great influence on mold filling of prefabricated body in circular tube. Orthogonal analysis of test results showed that the filling way have greatest effect on moldfilling, followed by the foaming time, then foaming temperature. The best foaming filling effect was heating 14 min or 16 min with the upper Al Si10(Ti H2)and the lower Al Si(Zr H2).(3) The preparation of sandwich panels with solder could significantly enhance the mechanical properties. Using the optimal orthogonal test results to study the special-shaped mould and the sectional view of the samples, when the foaming time was set to 20 min, the top temperature is 620 ? when filled special-shaped mould, the merge and the collapse of pore and discharge phenomenon between the film are more slight.