等离子热障涂层不同温度的氧化行为研究

Oxidation behavior of plasma sprayed thermal barrier coatings at different temperatures

采用扫描电镜(SEM)、能谱分析(EDXS)、图像分析仪等方法研究了典型等离子喷涂热障涂层在不同温度下的恒温氧化行为,探讨了热障涂层内氧化物的形成过程。结果表明,随着温度的升高,氧化速率常数值增加,粘结层中的Al发生贫化,粘结层中的氧化产物(TGO)层逐渐由氧化铝转变成以Ni、Cr为主的尖晶石类氧化物,热障涂层的氧化速率明显加快,并给出了温度与等离子喷涂热障涂层氧化速度常数之间的定量关系。

Oxidation behavior of plasma-sprayed thermal barrier coatings at different temperatures was studied with SEM, EDXS and image analysis, and formation of the thermally grown oxide （TGO）was also evaluated. The results show that with increasing temperature oxidation rate constant increases,composition of TGO is transformed from alumina to spinels comprising oxides of Cr/Ni, and oxidation of thermal barrier coatings accelerates. A quantitative expression between the temperature and oxidation rate constants is provided.