Study Of The Perparation Of Foamed Aluminum By Gas Injection

Foamed aluminum is a new kind of material with structural and functional properties combined.It will be widely used both in industries and the civil construction project.Preparation of foamed aluminum by gas injection is the most low-cost in all of the method because of its simple equipment and low cost.This method can realize continuous and scale production.In this paper,a kind of aluminum alloy which can broad foaming platform and reduce foaming temperature was selected to do experiment.Physical simulation experiment was done in order to examine effects of operating parameters on the foam structure.Furthermore,it was based on the analogy principle were performed in the static and dynamic states,respectively.In static state,the fluid in the tank was not stirred.Herewith the bubble behaviors in the water solution were recorded by photography.The influences of the gas feed rate, fluid viscosity were studied.Dynamic state experiments were carded out with a rotational impeller.Influences of the impeller shape,speed,size,position of the rotational shaft on the bubble behaviors and its change rule were investigated. Single factor experiments and low-temperature foaming experiments were carried out with self-making foaming device.Furthermore,technological parameter such as gas injection rate and style,content of stabilizer were changed in the experiments in order to investigate its influence on pore size.Laboratorial foaming experiments were carried out with self-making foaming device.The experiment includes two ways of gas injection which are continuous injection and pulse injection.Continuous casting simulation experiment also conducted with self-making foaming device.It turned out that Al-Sn alloy is an optimum alloy for low temperature foaming.The cell structure was greatly influence by orifice's diameter size,gas flow rate,fluid viscosity and gas injection way.The results show that the optimal processing which has excellent foaming effect is the foaming temperature 450℃,5%Al₂O₃,orifice diameter 0.5mm,gas injection rate 1.0L/min and running water cooling.The bubble growing and merging were restrained by the way of pulse gas injection.Running water cooling is more beneficial to foaming and grasping bubbles.Self-making maintaining device has good effect of heat insulation.