中文摘要：

采用半导体激光熔覆与等离子喷涂相结合的方法制备了YSZ/CoCrAlY热障涂层,利用扫描电镜（SEM）、X-射线衍射仪（XRD）分析了其高温氧化后的结构特征,建立了其高温氧化后应力特征的计算模型,并与拉曼显微光谱仪测试的应力进行了对比。结果表明：高温氧化后,粘结层组织为垂直于基体表面的树枝晶结构,陶瓷层出现细小裂纹与部分脱落现象,ZrO_2发生单斜相向立方相或正方相转变时伴随有4%的体积收缩,陶瓷层产生拉应力;ZrO_2发生立方相或正方相向单斜相转变时伴随有6%的体积膨胀,陶瓷层产生压应力;热障涂层经过750℃高温氧化108 h后,通过模型计算陶瓷层残余应力为496.5 MPa的压应力,与拉曼光谱测量结果（434.8 MPa）吻合得较好。

英文摘要：

Thermal barrier coatings were fabricated by diode laser cladding and plasma spraying processes.The model of residual stress was set up to calculate and analyze the residual stress of the thermal barrier coatings.Scanning electron microscopy（ SEM）,X-ray diffraction（ XRD） and micro-Raman spectroscopy were used to analyze the residual stress,microstructure and ceramic coat phases of the thermal barrier coatings.The results show that after high temperature oxidation at 750 ℃ for 108 h,the microstructure of the bond coat is dendrite structure which is perpendicular to the interface between the substrate and the bond coat,and there are micro cracks and exfoliations in the ceramic coat.ZrO_2 transforms from monoclinic to cubic phase or tetragonal phase accompanied by contraction of 4%volume and tensile stress is caused in the ceramica layer; ZrO_2 transform from cubic phase or tetragonal phase to monoclinic accompanied by expansion of 6% volume and compression stress is caused in the ceramica layer.The residual stress of the ceramic coating is about496.5 MPa compression stress after high temperature oxidation at 750 ℃ for 108 h,which is in good agreement with the measurement result（ 434.8 MPa） by Raman spectroscopy.