Study On Carbon Fiber/Inner Toughened Particles Composite Reinforced Aluminum Foam

Aluminum foam is a kind of high-quality porous material,which is usually used as a buffer energy-absorbing material.Foam aluminum has a wide yield platform,and absorbs energy through continuous deformation under almost constant stress.Because of its isotropy,it can absorb impact energy in all directions.In addition,foam aluminum is also lightweight and weldable Excellent properties such as resistance,corrosion resistance and no aging.Therefore,it has development potential in the fields of automotive,aerospace,military and other fields.However,aluminum foam has low strength,will deform under small compressive stress,and is easily broken.Therefore,the purpose of this experimental study is to stabilize the cell structure and improve the mechanical properties of aluminum foam by short carbon fiber/inner toughened particles And energy absorption characteristics.This experimental study modified the surface of carbon fibers by electroplating and sol-gel methods.Observation by infrared spectroscopy and microscopic morphology showed that the surface roughness of carbon fibers became larger and the oxygen-containing functional groups increased after carbon fibers were pretreated.In the experiment,the bath temperature range is 20-25?,and the voltage is 2.4 V.The best plating conditions for electroplating.No copper oxide phase appears in the copper layer soaked with boric acid,and the copper layer has good crystallinity,which does not affect the copper plating The mechanical properties of carbon fibers can obtain a complete,smooth and fine-grained electroplated copper layer.In the experiments of the surface modification of carbon fibers using the sol-gel method,the sol viscosity and scanning electron microscopy results show that at pH=9,TOES:deionized When water:ethanol=1:5:12,the coating effect of carbon fiber is the best.Melt foaming method was used to prepare copper-plated short carbon fiber reinforced aluminum foam material,and the cell structure and quasi-static compression mechanical properties of aluminum foam samples were studied.The results show that carbon fiber has a stabilizing effect on liquid gas foam,and the more carbon fiber is added,the better the foam stability.When the carbon fiber content is 1%,The mechanical properties of aluminum foam are low,and it is plastic deformation;when the carbon fiber content is 5%,The mechanical properties of aluminum foam are increased,and the compression curve shows a small range fluctuation,but it is still plastic deformation When the content is 7%,The mechanical properties of the aluminum foam material increase,but the soft stress stage appears in the compression curve,and the material gradually changes from plastic deformation to brittle deformation.In addition,from the material fracture analysis,the carbon fiber content is too high,and the aluminum foam appears brittle fracture,which is not conducive to energy absorption.The experiment further studied the addition of Mg element in carbon fiber reinforced aluminum foam.Experiments show that the addition of Mg can reduce the surface tension of the aluminum melt and improve the wettability between the solid particles and the aluminum liquid.When the carbon fiber content is 1%,The addition of Mg increases the mechanical properties of the foamed aluminum material,and the foamed aluminum material has excellent energy absorption ability;when the carbon fiber content is increased to 5%,The carbon fiber reinforced aluminum foam with Mg The mechanical properties decrease,mainly due to the high copper content.Copper and Mg form a needle-like alloy phase,which causes the plastic deformation ability of the matrix to decrease rapidly.The melt foaming method was used to prepare TiB2 particle reinforced aluminum foam materials.The effects of TiB2 content and metal Ca addition on the pore structure and mechanical properties of aluminum foam were studied.The results show that the presence of TiB2 particles accelerates the uniformity of the pore size,promotes the large pore size difference and the process of merging adjacent bubbles.When the TiB2 content is 5%,The promotion effect on adjacent bubbles is not obvious.The quasi-static compression test shows that the TiB2 content of 5%To 10%Can significantly improve the compressive strength of aluminum foam.When the TiB2 content is 5%,The foamed aluminum appears as plastic deformation,and when the TiB2 content is 10%,It appears as a brittle failure mode.In addition,the Ca content has a certain effect on the density of foamed aluminum.As the density increases,the yield strength and plateau strength of foamed aluminum also increase,but they all show a brittle foam deformation mode.