Studies On Preparation And Compressive Properties Of Aluminum Foams Matrix Interpenetrating Phase Composite Materials

As a new type of structural and functional materials,open-cell aluminum foams are often used in the fields of aerospace,automotive transportation,electronics,construction and military due to their excellent properties,such as low density,high specific strength,good energy absorption,good vibration reduction and noise reduction.Therefore,open-cell aluminum foams have a widely prospect in application.However,with the rapid development of modern industry,the properties of aluminum foams are required to be further improved,and it is very important to develop high performance aluminum foams matrix composites.Some studies have shown that aluminum foamsepoxy resin interpenetrating phase composite materials(IPC materials)were fabricated by filling epoxy resin(EP)into the pores of aluminum foams with high mechanical properties.On the basis of IPC materials,the aluminum foams-epoxy resin-fly ash cenospheres interpenetrating phase composites foams(IPC foams)were fabricated by introducing hollow cenospheres,which can exert the characteristics of each phase.IPC foams have an excellent energy absorption property besides good mechanical properties.It is a new research trend and direction to fabricate and research the IPC foams due to these advantages.In this paper,open-cell aluminum foams were prepared by infiltration casting method,and then IPC materials and IPC foams were fabricated.The effects of different EP contents on the compressive properties and energy absorption capacity of IPC materials were studied.In addition,the influence of different fly ash cenospheres(FACs)contents on the compressive properties and energy absorption capacity of IPC foams were investigated.The deformation behavior of aluminum foams,IPC materials and IPC foams were observed and analyzed under compressive load conditions,and the failure mechanisms were discussed.The results were listed as follows:1.Open-cell aluminum foams with uniform pore size distribution and good connectivity were obtained by infiltration casting method.With the increase of porosities,the compressive strength and energy absorption capacity of open-cell aluminum foams gradually decreased,but the yield plateau length gradually increased.The failure mechanisms mainly included the bending of aluminum foams strut and formation and expansion of local deformation bands.2.The IPC materials were fabricated by filling liquid EP into the pores of open-cell aluminum foams by negative pressure infiltration method.As the EP contents increased,the compressive strength of IPC materials increased,but the elastic modulus gradually decreased.Compared with aluminum foams,the compressive strength of IPC materials with different volume fractions(68%,73% and 78%)of EP is increased by 52.9 MPa,71.6 MPa and 72.7 MPa.When the strain is 0.5,the energy absorption capacity were increased by 41.74 MJ/m3,45.87 MJ/m3 and 48.77 MJ/m3.The compressive failure mechanisms mainly included the brittle fracture of EP,the bending of aluminum foams strut and the debonding of the interface.3.The IPC foams were fabricated by filling liquid EP and FACs into the pores of opencell aluminum foams by negative pressure infiltration method.With the increase of FACs contents,the compressive strength and energy absorption capacity of IPC foams decreased,but the stress fluctuation gradually reduced.The yield plateau region is extended,in addition,the energy absorption efficiency of IPC foams increased.Compared with aluminum foams,the compressive strength of IPC foams with different FACs contents(2 wt.%,4 wt.% and 6 wt.%)are increased by 68.33 MPa,66.05 MPa and 58.90 MPa.When the strain is 0.5,the energy absorption capacity are increased by 39.49 MJ/m3,35.35 MJ/m3,and 32.21 MJ/m3.When the contents of FACs were 6 wt.%,IPC foams had the highest energy absorption efficiency value(0.83),which is increased by 0.07 compared with the maximum value of aluminum foams.The failure mechanisms mainly included the bending of the aluminum foams struts,the brittle fracture of the EP,the crushing of the FACs,the debonding of EP/Al interface and EP/FACs interface.4.Based on the unit cell model,the prediction formula of IPC materials and IPC foams were established.It was proved that the formula could be used to predict the effective elastic modulus by comparing of predicted and experimental data.