热障涂层应力场的微拉曼光谱技术测试研究

采用等离子体喷涂工艺制备了热障涂层实验样品,在不同高温下进行热循环氧化实验。再应用微拉曼光谱法测量了热障涂层样品内残余应力场大小,并分析了试样尺寸、热处理温度和陶瓷涂层厚度对残余应力的影响。经历20次热循环氧化实验后,测得陶瓷涂层内残余应力由初始压缩应力值(-30~-20 MPa)逐渐变化到(-15~15 MPa),与文献3~7]结果比较一致。最后,用扫描电镜观察了试样截面形貌的变化。

Micro-Raman Spectroscopy Technique Applications to Measure Stress Fields in Thermal Barrier Coatings

Thermal barrier coatings(TBCs) samples made by plasma spraying technology were performed in thermal cyclic test at different high temperatures.The residual stress fields of thermal barrier ceramic coating were measured for every twenty thermal cycles by using micro-Raman spectroscopy technique.The influences of the ceramic coating thickness,thermal cycle times and cycle temperature on residual stress in TBCs were discussed in details.It is found that the residual stresses in the ceramic coating were compressive in the as-deposited samples with initial residual stress between-30 MPa and-20 MPa.After thermal cycle test,the stresses changed and the residual stress reaches between-15 MPa and 15 MPa.The experimental results were in agreement with the other investigation results.Finally,the cross-section morphologies of thermal barrier coatings were observed by SEM and discussed.