Proposal of new expressions for effects of splat interfaces and defects on effective properties of thermal barrier coatings

Based on the law of the conservation of energy, for the first time, novel mathematical formulations are proposed to quantify the influence of splat interfaces and defects on the effective properties of plasma sprayed thermal barrier coatings in spray direction, including the Youngʹs modulus and the thermal conductivity. Combined with finite element solution values and experimental results, a comparison between effect coefficients of splat interfaces and defects shows that splat interfaces account for about 75–80% of the total reduction in the effective Youngʹs modulus, and for about 55–70% of the total reduction in the effective thermal conductivity, indicating that the splat interfaces may have greater influences on the Youngʹs modulus than that on the thermal conductivity.