Numerical investigation of the effect of CMAS deposition on the temperature and stress distribution of thermal barrier coatings coated on a turbine blade

Particle deposition can cause significant damage to thermal barrier coatings (TBCs) and it is critical to understand the deposition characteristics and the stress distribution on the turbine blade. In this paper, the CMAS deposition characteristics is obtained by the critical velocity model. The temperature and stress distributions of TBCs and the blade is investigated by a thermal-fluid-solid coupling method. The particles with smaller diameters (<10 μm) are deposited on the pressure surface of the blade. The particles with larger diameters (>10 μm) are deposited on the suction surface of the blade. The most deposited amount is SiO2 particle, followed by CMAS particle and Al2O3 particle. The greater the wall roughness is, the more particle deposition. CMAS deposition reduces significantly the thermal insulation performance of the 8YSZ coating and increases the surface temperature of the blade, leading to the larger stress at the CMAS deposited regions. TBCs in the higher stress regions may eventually delaminate from the substrate under thermal stress and CMAS corrosion.