Fundamental Research On Continuous Preparation Of Aluminum Foam

Aluminum foam is filled with infinite number of pores. The presence of these small pores gives aluminum foam many excellent properties, such as energy absorbing properties, electromagnetic shielding performance, and mechanical damping properties and so on. Now aluminum foam has broad application prospects in transportation, construction, aviation aerospace industry, but it also failed to achieve continuous production industrialization, mainly due to the high cost of preparation of aluminum foam. The continuous production of technology can be a good solution to this problem to develop aluminum foam.In this paper, the raw material was TiH2 particles. After oxidation and chemical coating treatment, the decomposition characteristics of TiH2 were studyed. Then the dispersion characteristics of TiH2 added in the self-designed device were studyed. Finally, the effcects of dispersion temperature of foaming agent, dispersion time, stirring speed, Ca content, TiH2 content, foaming temperature, foaming time on pore structure of aluminum foam were studyed which lay the foundation for the continuous production of aluminum foam. The researchs show that:(1) The morphology of oxidized TiH2 particles is similar to as-received TiH2 particles. After further coated with SiO2,the surface of TiH2 particles form a SiO2/TiOx composite layer and the surface becomes smoother. The starting gas release time is retarded at least 125s at 650℃. However, the total amount of gas release is decreased with the increasing volume of Na2SiO3. A balance between the delay in gas evolution and the total gas release is achieved by oxidation with 400℃/6h+500℃/lh and coating with 50mL Na2Si03 (0.5mol/L).(2) The continuously, uniform dispersion of the blowing agent in the device is achieved and the parameters are:dispersion temperature of foaming agent is 645 ℃, dispersion time of foaming agent is 115s, stirring speed is 2500r/min, Ca content is 2.0wt%, TiH2 content is 0.9wt%.(3) By the devices of continuous addition of foaming agent, the continuous production of Al-Si12 alloy foam is achieved and the cell structure of Al-Sil2 alloy is uniform. The parameters for preparing A1-Si12 alloy foam configuration are as follows:dispersion temperature of foaming agent is 640 ℃, dispersion time is 110s, stirring speed is 2000r/min, Ca content is 2.5wt%, TiH2 content is 1.0wt%, foaming temperature is 630℃, foaming time is 6min.