多孔ZrO2-8 wt% Y2O3涂层的制备及性能

航空发动机的效率与转动叶片和机匣之间的间隙密切相关。为了控制转子和静子之间的间隙,需要在机匣表面制备可磨耗的封严涂层。在发动机的高温端,ZrO₂-8wt% Y₂O₃涂层是经常采用的封严涂层基体。涂层中的孔隙可以增加涂层的可磨耗性。本文利用聚苯酯(PHB)增加等离子喷涂的ZrO₂-8 wt% Y₂O₃涂层的孔隙率。为了避免聚苯酯在等离子喷涂过程中的烧损,利用溶胶-凝胶法在聚苯酯颗粒表面沉积一层TiO₂层。文中将讨论采用此方法制成的涂层的形态、孔隙率、硬度和可磨耗性。结果表明,在喷涂粉末中混合包覆型的聚苯酯后,涂层的孔隙率将会得到提升,涂层硬度将会下降。磨耗试验的结果表明涂层的磨耗深度随着涂层孔隙率的增加而增加。

Formation and Properties of Porous ZrO2-8 wt% Y2O3 Coatings

The efficiency of a gas turbine engine is highly dependent upon the clearance between blades and engine case. To control the over-tip leakage, an abradable coating system is sprayed on the case surface. In the high temperature section, a ZrO₂-8 wt% Y₂O₃ (YSZ) coating is usually applied as matrix. Pores in the coating are to enhance their abradability. In this study, poly-p-hydroxybenzoate (PHB) powder was used as a pore-forming material. To avoid burning loss of PHB during the spraying process, a sol-gel method was utilized to coat a TiO₂ shell on the PHB powder surface. The characteristics of the coatings were investigated in this work, such as morphology, porosity, hardness and abradability. The results show that the coated PHB improved the porosity of the YSZ coating, and then decreased the coating hardness. Finally, an abradability test was utilized to exhibit the incursion depth increased with the increase of coating porosity.