热障涂层残余应力的拉曼光谱测量及数值分析

 为了研究航空发动机热障涂层(TBCs)制备过程中残余应力的分布问题,采用大气等离子喷涂技术(APS)在镍基高温合金GH99上制备了热障涂层(CoCrAlY粘结层和ZrO₂陶瓷面层),对热障涂层进行了100~3 500 cm^-1激光拉曼光谱扫描,并采用有限元方法计算了与之对应的热障涂层有限元模型应力分布.分析了涂层系统内部轴向残余应力的分布情况并对比分析了激光拉曼光谱频移及有限元计算结果.激光拉曼分析结果表明:轴向陶瓷层内部呈现压应力,在陶瓷层/粘结层界面处应力达到最大值14.8 MPa,粘结层内呈现拉应力;数值分析应力变化趋势与激光拉曼测试分析结果相吻合.

Study of Residual Stress of Thermal Barrier Coatings by Raman Spectroscopy and Numerical Analysis

Residual stress of thermal barrier coatings(TBCs) is investigated by experiment and numerical method.Thermal barrier coatings,which consist of CoCrAlY bond coating(BC) and ZrO2 thermat ceramic coating(TCC) are fabricated on the GH99 superalloy by air plasma spray(APS).Meanwhile,residual stress in TBCs during the cooling process is measured by 100-3 500 cm-1 Raman spectroscopy and simulated using finite element method(FEM).The distributions of vertical stresses are analyzed;meanwhile,the results of Raman shift and numerical simulation are compared.The results show that in the vertical direction,there appears compressive stress in TCC,and to the interface of TCC/BC there shows the maximum compressive stress,14.8 MPa.There appears tensile stress in BC.The results of the simulation are consistent with experimental measurements obtained with micro-Raman spectroscopy.