YAG/8YSZ双陶瓷热障涂层等温氧化性能研究

Isothermal Oxidation Properties of YAG/8YSZ Double Ceramic Thermal Barrier Coatings

对比研究了YAG/8YSZ双陶瓷和8YSZ单陶瓷热障涂层体系的抗高温氧化性能。采用爆炸喷涂(D-GUN)在310S耐热不锈钢基体上制备粘结层(NiCoCrAlY),用大气等离子喷涂(APS)分别在粘结层试样上制备YAG/8YSZ双陶瓷和8YSZ单陶瓷热障涂层,利用SEM和XRD分析涂层氧化前后截面与表面特征,对比研究2种热障涂层体系在1100℃等温氧化不同时间后的氧化增重动力学、YAG陶瓷层微观结构与物相及TGO生长过程和生长动力学。结果表明,YAG陶瓷层在1100℃等温氧化200h后无明显相结构转变,孔隙率稍有降低;YAG/8YSZ双陶瓷层体系较8YSZ单陶瓷层体系氧化增重速率降低1.7倍,TGO生长速率降低1.4倍,粘结层β-NiAl相消耗速度及岛状氧化物生长速度更低,表现出更好的抗高温氧化性能。

The high temperature oxidation resistance of YAG/8 YSZ double ceramic and 8 YSZ single ceramic thermal barrier coatings system were analyzed. The bond-coat(NiCoCrAlY) was deposited on a 310 S heat-resistant stainless steel substrate by detonation gun spraying, and YAG/8 YSZ double ceramic and 8 YSZ single ceramic thermal barrier coatings were deposited on the bond-coat by air plasma spraying(APS). The cross-section and surface characteristics of the coating were analyzed by SEM and XRD before and after oxidation. The oxidative mass gain kinetics, microstructure, phase of the YAG ceramic layer, and the TGO growth process and growth kinetics of the two thermal barrier coating systems were comparatively investigated after isothermal oxidation at 1100 °C. The results show that the YAG ceramic layer shows no obvious phase transformation after isothermal oxidation at 1100 °C for 200 h, and the porosity is slightly reduced. The oxidation mass gain rate and TGO growth rate of YAG/8 YSZ double ceramic layers system are 1.7 times and 1.4 times lower than those of 8 YSZ single ceramic layer system, respectively. The double ceramic layer system shows lower β-NiAl phase consumption rate and island oxide growth rate, which results in a better high temperature oxidation resistance.