Study On Preparation And Compressive Properties Of Open Cell Aluminum Foam

The open-cell aluminum foam material is an engineering material with light weight,energy absorption and buffering,sound absorption,heat dissipation,electromagnetic shielding,fire resistance and flame retardant performance characteristics.It has broad application prospects in many fields such as aviation,aerospace,communications,chemical industry,environmental protection,and biology.The infiltration casting method is currently the main process for preparing open-cell aluminum foam.It has the characteristics of controllable structure,simple process,and low production cost.It is still difficult to remove the pore-forming particles cleanly and affect the final use performance of open-cell aluminum foam.In this thesis,firstly,pore-forming particles of various materials were prepared by a disc granulator and their strength and collapsibility were compared.The results show that the salt ball granules have the best collapsibility and strength combination,and have the ability to change at high temperature.Therefore,hot press sintering can be used to improve the density of the salt ball preform.Experiments show that this process can realize the adjustment of the porosity of open-cell aluminum foam in the range of 65%-85%.On this basis,this thesis developed a production line that can mass produce 500*500*Xmm open-cell aluminum foam materials,designed a percolation mold and optimized percolation process parameters.Finally,the batch preparation of large-size open-cell aluminum foam ingots was successfully realized.Finally,the thesis also studied the compressibility and energy absorption capacity of open-cell aluminum foam.Experiments show that open-cell aluminum foam is not an energy-absorbing material with a constant compression platform stress.Under different allowable stress conditions,the energy absorption and protection effect of open-cell aluminum foam does not change monotonously with the pore structure parameters,but there is an optimal pore structure parameter value.For each open-cell aluminum foam with certain pore structure parameters,there is an optimal use stress condition,under which its energy absorption capacity is higher than that of open-cell aluminum foam with other pore structure parameters.For open-cell aluminum foam samples with a pore size of 2?2.5mm and a relative density of 0.37,the energy absorption capacity can reach 20.2 MJ/m3 under the best conditions.