Preparation And Anti-corrosion Performance Of Vertically Few-layer Graphene On Zirconium Alloy

Zirconium alloy has a small neutron absorption cross section,irradiation stability,sufficient mechanical strength,compatibility with coolants,fission products and fuels,and excellent processing properties make it a cladding material for nuclear reactors.With the increase of nuclear reactor fue l consumption,it is urgent to improve the corrosion resistance of existing zirconium alloy cladding.Graphene and vertical few-layer graphene because of its special structure and excellent thermal conductivity,chemical stability,super-hydrophobic,so that it has great potential in the field of anti-corrosion.In this paper,the PECVD method was used to study the corrosion resistance and oxidation resistance of the vertical graphene on the zirconium surface.The corrosion resistance mechanism was discussed.In this paper,the vertical graphene thin films were prepared by PECVD method.By optimizing the process parameters,wo knows that when the gas flow ratio was Ar / CH4: 10: 90,the temperature was 600?,the growth time was 60 min and the pressure was 500 Pa,We can get the least defective,the highest degree of super-hydrophobic structure of graphene,the wetting angle of 119 °.The analysis of the interface structure between VFG and zirconium matrix sho wed there existed the Crystalline carbon layer between VFG and zirconium alloy,besides the analysis of high resolution scanning electron microscopy showed VFG height is about 100 nm,transmission electron microscopy showed that VFG layer number is 3-5,which belongs to the few layer graphene.The long-term immersion test and electrochemical performance of NaCl solution and KOH solution show that the corrosion resistance of zirconium alloy changes with time,and then increases sharply and then increases again and again.The fluctuation is obvious and the change is more than 5000 k?cm2,due to the continuous formation and shedding of the passivation film under the action of corrosive solution The corrosion resistance of Zr-VFG(500Pa)sample is less than 100 k? cm2,which can play a very good protective effect on the zirconium alloy matrix,and it shows excellent corrosion resistance.The high temperature oxidation experiments show that zirconium alloy has lower antioxidant capacity at 300 ?;and the average weight gain rate of zirconium alloy covered with VFG which prepared at 700 Pa is 0.0638 mg mg/dm2 h,which belongs to the oxidation level;and and the average weight gain rate of zirconium alloy covered with VFG which prepared at 500 Pa is 0.0089 mg/dm2 h,which belongs to the complete oxidation level,so the VFG has better antioxidant properties.Study on antioxidant mechanism of VFG found that the high stability,strong anti permeability and special interface structure of graphene determined its antioxidant properties.