Spherical Gd2Zr2O7 hollow powders with a mean size of 8.8 μm were fabricated as feedstock for thermal barrier coatings (TBCs) by spray-drying. The single-ceramic-layer (SCL) Gd2Zr2O7 TBCs and double-ceramic-layer (DCL) Gd2Zr2O7/YSZ TBCs with quasi-columnar structure were successfully fabricated by plasma spray-physical vapor deposition (PS-PVD). Tensile and water-quenching tests were applied to evaluate TBCs performances. The results show that adhesion strength of SCL Gd2Zr2O7 TBCs and DCL Gd2Zr2O7/YSZ TBCs is 36.5 MPa and 15.4 MPa, respectively. The delamination of SCL Gd2Zr2O7 TBCs and DCL Gd2Zr2O7/YSZ TBCs in the tensile test takes place at the middle and bottom of Gd2Zr2O7 layer, respectively, due to relatively lower fracture toughness of Gd2Zr2O7 layer. After 40 cycles of water-quenching test, DCL Gd2Zr2O7/YSZ TBC surface keeps relatively intact, while SCL Gd2Zr2O7 TBC surface shows 20% visible destroyed regions, which demonstrates that DCL Gd2Zr2O7/YSZ TBCs have a better thermal shock resistance than SCL Gd2Zr2O7 TBCs. The cracks in the SCL system propagate near thermally grown oxide (TGO) due to thermal mismatch and TGO growing stress, while cracks in the DCL system propagate in the Gd2Zr2O7 layer due to its relatively lower fracture toughness.

中文翻译：

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等离子喷涂物理气相沉积制备的新型 Gd2Zr2O7 和 Gd2Zr2O7/YSZ 热障涂层的比较

通过喷雾干燥制备平均尺寸为 8.8 μm 的球形 Gd2Zr2O7 中空粉末作为热障涂层 (TBC) 的原料。通过等离子喷涂物理气相沉积（PS-PVD）成功制备了具有准柱状结构的单陶瓷层（SCL）Gd2Zr2O7 TBC和双层陶瓷（DCL）Gd2Zr2O7/YSZ TBC。应用拉伸和水淬测试来评估 TBC 的性能。结果表明，SCL Gd2Zr2O7 TBCs和DCL Gd2Zr2O7/YSZ TBCs的粘合强度分别为36.5 MPa和15.4 MPa。由于Gd2Zr2O7层的断裂韧性相对较低，拉伸试验中SCL Gd2Zr2O7 TBCs和DCL Gd2Zr2O7/YSZ TBCs的分层分别发生在Gd2Zr2O7层的中部和底部。经过40次循环水淬试验，DCL Gd2Zr2O7/YSZ TBC表面保持相对完整，而SCL Gd2Zr2O7 TBC表面显示20%的可见破坏区域，这表明DCL Gd2Zr2O7/YSZ TBC比SCL Gd2Zr2O7 TBC具有更好的抗热震性。由于热失配和 TGO 生长应力，SCL 系统中的裂纹在热生长氧化物 (TGO) 附近扩展，而 DCL 系统中的裂纹由于其相对较低的断裂韧性而在 Gd2Zr2O7 层中扩展。