Process Optimization and Finite Element Simulation for Preparing Ultra-Thick Thermal Barrier Coatings with Vertical Cracks

To meet the urgent demand of high-performance and ultra-thick thermal barrier coatings (TBCs) for key hot end components of gas turbine engines, in this work, a series of ~ 2-mm-thick yttria-stabilized zirconia (YSZ) coatings with vertical cracks were fabricated by a wide-velocity range high-energy plasma spraying technology. The effects of different process parameters on the density of vertical cracks were studied experimentally and through numerical simulation. The results suggested that the vertical crack density increased with increasing spraying power and decreasing standoff distance. When the temperature difference between the coating surface and the back of the substrate increased by approximately 95 °C, the vertical crack density increased by 1 crack/mm.