CeO_2对等离子喷涂Cr_2O_3涂层抗热震性的影响

Effects of Additive CeO_2 on Thermal Shock Resistance of Plasma Sprayed Cr_2O_3 Coating

在Cr2 O3陶瓷粉末中添加不同量的CeO2 ,探讨CeO2 对等离子喷涂涂层抗热震性的影响 ,认为涂层的热震失效机制是在循环应力作用下发生在陶瓷层 粘结层界面的疲劳失效。在等离子喷涂Cr2 O3涂层中添加 3 %CeO2 后 ,热震起裂寿命及失效寿命均得到明显提高。适量的CeO2 使微裂纹呈网状分布于涂层薄片内 ,具有释放涂层内应力的作用 ,可延缓裂纹的起裂和扩展 ,并使涂层内贯穿性孔洞减少 ,从而显著提高涂层的抗热震性能。

The influence of CeO 2 with different content on the thermal shock resistance of plasma sprayed Cr 2O 3 coating was investigated. The thermal shock failure mechanism of coating was also studied. It is found that the thermal shock failure mechanism of coating is thermal stress fatigue destruction, and the destruction takes place at interface of ceramic and bond coating. The experimental results show that the lifetime of coating fracture and failure increase considerably when 3%CeO 2 is added into the plasma sprayed Cr 2O 3 coating. The suitable content of CeO 2 makes the microcracks exist in network form. The microcrack net can release internal stress in coating, delay the crack forming and expanding and decrease holes in coating. Thus the thermal shock resistance increase largely.