Study On The Fracture Performance And Galvanic Corrosion Resistance Of Carbon Fiber/Aluminum Laminated Composite Structure

Carbon fiber reinforced aluminum composites have the characteristics of high strength,high modulus and lightweight,so it is widely used in the aerospace,satellite,automobile,ship industries and other fields.However,in practical application,whether carbon fibers and aluminum alloys are connected by riveting,or bonding,the two materials with potential difference will inevitably have contact with each other.In rainy and snowy weather,humid climate or marine environment,galvanic corrosion may occur.Therefore,it is particularly important to improve the galvanic corrosion protection performance while improving the mechanical properties of the carbon fiber/aluminum composite material.In order to solve this problem,aramid fiber film was introduced into the bonding layer of carbon fiber/aluminum laminated composite structures to strengthen the bonding interface of the composites,and to protect the materials from galvanic corrosion behavior.Based on the ENF three-point bending test,SEM observation,EDS element analysis,etc.were used as research methods,the enhancement and the galvanic corrosion protection mechanism of the composite materials by the aramid fiber,the main research contents and results include:(1)In order to strengthen the bonding interface,the aramid fiber films with resin was introduced into the bonding layer of carbon fiber aluminum laminated composite structure to composite.Compared with the pure resin interface,the 1mm aramid fiber film increased the limit load of the structure by 9.7%.Aramid fiber can effectively strengthen the interface and hinder the crack propagation along the bonding layer.At the same time,the SEM electron microscope was used for microscopic observation,and the cooperative bridging between aramid fibers was studied.(2)Because of the insulation of aramid fiber,it can block the contact between carbon fiber and aluminum alloy to a certain extent,delay the occurrence of galvanic corrosion and reduce structural corrosion damage.After the accelerated corrosion simulation test,the 1mm aramid fiber film reduced the structural ultimate load by only 8.40% compared with the structure without corrosion test,and increased by 28.69% compared to the pure resin interface structure after the corrosion test.At the same time,the mechanism of galvanic corrosion protection of aramid fibers was analyzed by SEM and EDS.(3)The effects of three kinds of aramid fibers with different lengths and the combination of aramid fibers with different lengths on the mechanical properties and galvanic corrosion protection performance of the carbon fiber aluminum laminated composite structure were studied,and the better parameters were selected based on this.The results show that the 1mm aramid fiber/reinforced composite structure has the best galvanic corrosion protection performance,after the corrosion test,the ultimate load only drops by 8.40%,while the 3mm aramid fiber/reinforced structure has the best mechanical properties,compared with the pure resin adhesive layer,the ultimate load is increased by 36.4%,and after corrosion test,the ultimate load is increased by 49.52% compared with the pure resin structure.