Ba(Mg_1/3Ta_2/3)O₃热障涂层的制备及抗热震性能

Ceramic powder Ba(Mg_1/3Ta_2/3)O₃ (BMT) was synthesized by the solid-phase synthesis method with the raw materials powder of BaCO₃, MgO, and Ta₂O₅. Then BMT/YSZ coatings were prepared by atmospheric plasma spraying (APS). The phase composition and microstructure of the BMT powder and coatings were analyzed by XRD, SEM and optical microscope. The thermal shock resistance was evaluated by water quenching. The results show that the BMT powder with perovskite structure can be synthesized at 1450 ℃ for 4 h. The BMT powder reveals desirable phase stability. The BMT/YSZ coatings have a compact microstructure and higher binding strength between each coating. Spallation is observed within the BMT coatings after 9 cycle thermal shock testing from 1150 ℃ to room temperature. Low fracture toughness of BMT and the precipitation of Ba₃Ta₅O₁₅ phase are the main reasons for failure of BMT/YSZ coatings.