Formation of t’-YSZ nanocoating from composite sols

Abstract

The non-equilibrium tetragonal (t’) yttria doped zirconia (YSZ) nanocoating was prepared by dip coating the substrate in the composite sols of monoclinic ZrO₂ and Y₂O₃ and annealing at moderate temperature. The as prepared coating was characterised by SEM, X-ray diffraction and Raman spectra. It was shown that a dense and uniform t’-YSZ coating consisting of particles ∼30 nm was prepared. The nanostructures of the particles in the ZrO₂ and Y₂O₃ sols ensured that a uniform and dense coating consisting of small particles was formed at moderate temperature. Compared with the precursor sols, the sintering temperature using the composite sols of ZrO₂ and Y₂O₃ was decreased by 500°C. It indicated that the as prepared coating could be used more widely because more substrates were suitable under the low sintering temperature.

Keywords:

• Thermal barrier coatings
• Yttria
• Zirconia
• Non-equilibrium tetragonal phase
• Composite sols
• Monoclinic

The authors acknowledge the supports of Shanghai Leading Academic Discipline Project (grant no. S30107), Research & Innovation Projects of Shanghai Education Commission (grant no. 11YZ22), Project of Shanghai Environment Condition (grant no. 10dz2252300), Postdoctoral Foundation of Shanghai University, Science Foundation for Excellent Youth Scholars of Shanghai University and Science Foundation for Excellent Youth Scholars of Universities (Shanghai).