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

摘要： 为在氧化钇稳定氧化锆(YSZ)热障涂层表面制备具有优异力学性能及抗盐雾腐蚀性能的氧化锆基涂层,以电熔氧化钇稳定氧化锆为主原料,以Al(H₂PO₄)₃、SiO₂溶胶为黏结剂,经刷涂与热固化得到氧化锆基涂层。探究不同黏结剂添加量(SiO₂溶胶质量分别占Al(H₂PO₄)₃质量的0、10%、20%、30%和100%)对涂层显微结构、力学性能和抗盐雾腐蚀性能的影响。结果表明:1)适量SiO₂溶胶和Al(H₂PO₄)₃之间的协同作用可促进涂料网状结构生成,有效消除了固化过程的收缩和起泡现象,改善涂层质量,进而提高抗盐雾腐蚀性能。2)SiO₂ 溶胶在高温下会与氧化锆反应生成ZrSiO₄,导致涂层结构破坏,热冲击时内部产生的热应力会导致涂层开裂,1 400 ℃下抗热冲击寿命大幅度降低;未添加SiO₂溶胶的涂层抗热冲击性能最优,但强度、硬度较低。3)当SiO₂溶胶质量占Al(H₂PO₄)₃质量的20%时,涂层综合性能最佳,其拉伸强度为16.08 MPa,维氏硬度为597 HV,抗盐雾腐蚀寿命为166 h。

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