关键词: 磷酸盐氧化锆基涂层, SiO₂溶胶, 抗盐雾腐蚀性能, 力学性能

Abstract: In order to prepare zirconia-based coatings with excellent mechanical properties and salt fog corrosion resistance on the surface of yttria-stabilized zirconia (YSZ) thermal barrier coatings,zirconia-based coatings were obtained using fused yttria-stabilized zirconia as the main raw material,Al(H₂PO₄)₃ and SiO₂ sol as binders,followed by brush coating and thermal curing.The effects of different binder additions (silica sol addition accounts for 0,10%,20%,30%,and 100% of the Al(H₂PO₄)₃ addition,by mass) on the microstructure,mechanical properties,and salt fog corrosion resistance of the coatings were investigated.The results show that:(1)the synergistic effect of an appropriate amount of silica sol and Al(H₂PO₄)₃ promotes the formation of a network structure in the coating paste,effectively eliminating shrinkage and bubbling during curing,improving the coating quality,and enhancing the corrosion resistance;(2)silica sol reacts with zirconia at high temperatures to form ZrSiO₄,leading to structural damage in the coating;during thermal shock,the internal thermal stress causes cracking,significantly reducing the service life under thermal attack at 1 400 ℃;the coating without silica sol exhibits the best thermal shock resistance but low strength and hardness;(3)when the silica sol addition accounts for 20% of the Al(H₂PO₄)₃ addition,the optimal overall performance can be obtained,with a tensile strength of 16.08 MPa,Vickers hardness of 597 HV,and service life of 166 h under salt fog corrosion.

Key words: phosphate zirconia-based coatings, silica sol, salt fog corrosion resistance, mechanical properties