Study On Bending Properties Of Aluminum Foam Sandwich

Aluminum foam sandwich board,as a new type of structure-function integrated material,has a series of advantages such as low density of aluminum foam material,good buffering and energy absorption and so on.At the same time,it overcomes the disadvantages of single aluminum foam material which has poor strength and is difficult to be used as structural material.It has broad application space in automobile,national defense,aviation,aerospace,construction and other fields.The preparation methods of the foamed aluminum sandwich panel include gluing method,welding method,powder metallurgy method and so on.Since aluminum foam sandwich panels are inevitably subjected to a certain degree of flexural bending load in actual application scenarios,it is necessary to study the bending performance of aluminum foam sandwich panels.The response of aluminum foam sandwich panels was investigated under quasi-static three-point bending load.The adhesive method and the precursor foaming method were used to prepare the aluminum foam sandwich panels.The experiment mainly used the adhesive method to prepare the aluminum foam sandwich panels with physical interface.Four kinds of aluminum foam were prepared by melt foaming method,including three types of pure aluminum matrix aluminum foam core materials,with densities of 0.37g/cm3,0.57g/cm3 and 0.75g/cm3 respectively,and a foam aluminum core material with a matrix composition of 7.5%TiB2-4.5%Cu-Al and a density of 0.75g/cm3,using Carbon Fiber Reinforced Plastics(CFRP),6061 aluminum alloy and TC4 titanium alloy three kinds of lightweight material panels.In addition,the preform foaming method was used to directly foaming to prepare aluminum foam sandwich panels with metallurgical bonding interface.The experiment has achieved the following research results:(1)The load-displacement curves of three-point bending test of the aluminum foam sandwich panel composed of CFRP panel and pure aluminum foam aluminum is composed of the following four stages,or includes the following four stages,respectively:linear elastic stage,nonlinear growth stage,instability stage and compaction stage;(2)The failure modes of aluminum foamed sandwich panels with CFRP panels mainly include collapse at loading point,core shear and interface debonding failure.For sandwich panels with pure aluminum core,the bending resistance of sandwich plate increases with the increase of the thickness of the panel,the thickness of the core material and the density of the core material;for the sandwich panels with composite matrix core material,compared with the sandwich panels with the same density of pure aluminum matrix core material,when the thickness of the panel is 1.0mm,the peak load increased little,but the displacement of the peak load is significantly earlier.When the thickness of the panel is 2.0mm,the peak load is increased by 21.2%,and the time of debonding failure is significantly earlier;(3)For the aluminum foamed sandwich panels with different material panels,the maximum peak load is TC4 titanium alloy,followed by CFRP,and the minimum is 6061 aluminum alloy.The collapse area of the core is mainly located below the loading point of the aluminum foam sandwich panels with CFRP panels.The collapse area of the core of aluminum foam sandwich panels with metal panels is larger,and the collapse area is the foam core material between the two supports;(4)Adding CFRP between the TC4 titanium alloy panel and the foam aluminum core layer to prepare a multi-layer composite aluminum foam sandwich panel,which can greatly improve the bending resistance of the sandwich panel,its peak load is increased by 53%,and the displacement when debonding failure occurs increased by 70%;(5)For the aluminum foam sandwich panel with the metallurgical bonding interface,the core material mainly occurs shear failure in the three-point bending test,and a plastic hinge forms at the single support.