Quantitative radiographic non-destructive evaluation (NDE) of advanced structural ceramics

Qualitative NDE information retrieval is enhanced using digital image processing methods on radiographic images of advanced structural ceramics. The improved defect detectability facilitates establishing accept/reject criteria. It is shown that microfocus-based radiographic NDE results are essential for ceramic manufacturing process control. The application of image processing routines permits extraction of quantitative NDE information, eg relating to ob density variations, void size distribution, impurities etc. This information is important, not only for ceramic manufacturers, but also for qualitative as well as quantitative condition monitoring of advanced ceramic components. Practical examples are used for documentation of the image processing capabilities for qualitative and quantitative radiographic NDE. Quantitative results may be retrieved following special calibration procedures, involving X-ray spectrum determination and linear attenuation coefficient calculation, camera calibration and image artifact corrections. However, despite numerous calibration and calculation procedures, object density determinations remains semi-quantitative, due to the X-ray path length dependence of the linear attenuation coefficient.