Evolution characteristic of inner stress for the standing nanostructured YSZ thermal barrier coatings fabricated by thermal spraying 3D-printing: A numerical simulation study

Thermal spraying 3D-printing (TS3DP) is a very effective method to fabricate the standing coating including metallic coating and ceramic coating. In the current work, the nanostructured YSZ (yttria stabilized zirconia) thermal barrier coatings (TBCs) was fabricated by TS3DP in a graphite mold by Computer Aided Design (CAD). The evolution characteristics of inner stress for the YSZ TBCs has been calculated via finite element modeling. The splats were deposited and arranged in the graphite mold layer by layer, the coating can be formed based on the concept of additive manufacturing. The graphite mold was used as the holder substrates, residual stress will be induced at the inner of the coating, with the dimension of the standing coating increasing, micro-pores and micro-cracks which were distributed randomly will be formed at the inner of the coating which will further affect the inner stress distribution of the YSZ standing coating, partial micro-pores and micro-cracks will release the stress concentration of the standing coating at a certain degree. The inner stress can be eliminated by the post annealing treatment. It can be predicted that the standing YSZ coating have enhanced toughness and improved thermal insulation effect, and may be also used as buck ceramic materials.