Numerical analysis of the influence of pore microstructure on thermal conductivity and Young's modulus of thermal barrier coating

Abstract

In this paper, the thermal conductivity and Young's modulus of the thermal barrier coating (TBC) system with various pore morphologies are numerically investigated. A multi-parameter random grown method, based on the quartet structure generation set algorithm, is adopted to generate the TBC model with simulation realistic pore microstructure. The morphological parameters of the pores include total porosity, pore size, pore aspect ratio and pore angle. The thermal conductivity and Young's modulus of coatings with different pore morphologies are discussed by the finite element method. The results show that the total porosity, pore aspect ratio, and pore angle have significant effects on the thermal conductivity and Young's modulus of TBC. Coating with pores arranged in the direction of 0° has the lowest thermal conductivity and the largest Young's modulus. With the change of pore angle, the thermodynamic properties show a different positive or negative correlation with the range of the pore aspect ratio. Besides, coating with small pore size has superior thermal insulation performance and thermal mismatch mechanical properties. The structural construction method and analysis method can also be applied to the field of materials with porous structure.