Study On The Effect Of Ion Irradiation On The LBE Corrosion Resistance Of TiAlN Coating

Lead-bismuth eutectic(LBE)is used as a coolant for lead-cooled fast reactor(LFR)due to its high thermal conductivity,low melting point,high boiling point and other excellent physical properties and low chemical activity.It is also an important candidate material for coolant and spallation targets in subcritical reactors of accelerator driven subcritical system(ADS).However,the contact between LBE and structural materials will cause corrosion of materials,leading to deterioration of material performance,and become one of the bottlenecks restricting the development of LFR and ADS lead-cooled reactors.TiAlN coatings has great potential for development in the protection of structural materials facing LBE due to its high resistance to radiation,high temperature oxidation,corrosion and chemical stability.This thesis takes TiAlN coatings as the research object,and studies the effect of ion irradiation on the LBE corrosion resistance of TiAlN coatings.First,the cathode arc ion plating technology is used to prepare TiAlN coatings(with Cr as the transition layer)on the surface of the W-Fe-Ni alloy material,and then perform the N⁵⁺ion irradiation with a dose of 1.0 Me V(0-2.0)×10¹⁶ ions/cm² according to the experiment,the radiation peak damage level reached 1.0 dpa and 5.0 dpa.And then they were corroded in the static LBE with saturated oxygen at 450?for 500h,1000h and3000h,respectively.After the experiment,morphology of the surface and cross-section of the sample was observed by scanning electron microscope(SEM);the element distribution of the surface and cross-section was analyzed by energy dispersive spectrometer(EDS);X-ray diffraction(XRD)and X-ray were used Energy dispersive spectroscopy(XPS)analyzed the micro-combination of the coating and the chemical valence state of the new oxide;the transmission electron microscope(TEM)was used to observe the formation of the near-surface oxide layer of the corroded sample after irradiation;finally,the scratch tester was used to the irradiated and corroded samples were analyzed for changes in bonding force.Through a series of test analysis,the effect of N⁵⁺ion irradiation on the LBE corrosion resistance of TiAlN coating was evaluated.The findings of this paper:(1)TiAlN coating exhibits good radiation resistance performance at an irradiation dose of up to 2.0×10¹⁶ ions/cm²;however,as the irradiation dose increases,the residual stress first decreases and then increases.The change indicates that the lattice constant and the binding force have increased first and then decreased.(2)After 3000 hours of corrosion,no corrosion phenomena such as dissolution and LBE penetration of the TiAlN coating surface were observed,and Al₂O₃ and Ti O₂were only generated near the surface defects.The coating exhibits good corrosion resistance under this corrosive condition.(3)The thickness uniformity of the oxide layer on top of the TiAlN samples ofter LBE corrosion with irradiated by N⁵⁺ion is improved;with the increase of the irradiation dose,the lattice constant of the LBE high temperature corrosion samples decreases;under 3000h long aging,the irradiation will bond the coating The influence of force is small.