热障涂层喷涂质量微焦点CT检测

采用微焦点X射线源对热障涂层样品进行了高分辨率X射线成像研究,采用多尺度对比度增强算法提高了热障涂层与基体之间的对比度.X射线图像显示热障涂层各处厚度差异较大,热障涂层内部可能存在大量孔隙.通过微焦点计算机层析成像(CT)对样品进行了高分辨率CT扫描与重建,得到了样品的CT重建图像.从热障涂层CT图像观察到热障涂层内部存在大量孔隙,且不同层孔隙尺寸、数量不同.结合3个坐标方向的切片图像分析了热障涂层深度方向的热障涂层厚度,得到了热障涂层厚度的二维分布,测量得到热障涂层平均厚度约为40μm.对沿热障涂层深度方向850~1131层切片图像,利用可视化软件VGstudio MAX得到了热障涂层内部孔隙三维分布.研究结果表明:微焦点CT可用于热障涂层制备工艺质量检测. 

Spraying quality inspection of thermal barrier coating by micro-computed tomography

Specimen of thermal barrier coating (TBC) was inspected by high resolution X-ray imaging with a microfocus X-ray source,while multiscale contrast enhancement for X-ray image was performed,and the contrast between the coating and substrate was improved.X-ray images show that thickness of TBC is different in different positions,and many voids may exist in the interior of TBC.The specimen of TBC was scanned and reconstructed by high resolution microfocus X-ray computed tomography(CT),and slice images in different cross sections were obtained.CT images show that voids exist in TBC,and the size and quantity of voids are different in different cross sections.Combined with slice image analysis from three coordinate directions,thickness of TBC along deepth direction was analyzed,and two-dimensional distribution of TBC thickness was achieved.Average thickness of TBC is approximately 40 μm.The slice images from slice 850 to slice 1131 along deepth direction were visualized by the software of VGstudio MAX,and 3-D distribution of voids was displayed.Research results show that micro-computed tomography can be used to inspect the quality of thermal barrier coating.