Toward Durable Thermal Barrier Coating with Low Thermal Conductivity Superiority: Material Design, Process Optimization and Performance Evaluation

The aim of this work is to find a path toward a thermal barrier coating (TBC) that is more thermally stable and less thermally conductive than current 8YZS coatings. The concept of dual-phase composite ceramics is proposed in an effort to combine the desirable attributes of unique phase constitution, low conductivity, and high ceramic fracture toughness. In addition, efforts are made to optimize the spraying process for low-k ceramic topcoats by controlling the effect of key parameters on porosity, deposition rate, and deposition efficiency. Isothermal oxidation and thermal cycling tests are conducted to evaluate the performance of the low-k TBCs with promising results.