Application of X-ray phase-contrast imaging technique in the study of pyrocarbon-coated zirconia kernels

X-ray in-line phase-contrast imaging is an emerging technique made practical by high brilliance synchrotron X-ray sources and high-performance X-ray detectors. This technique is capable of providing improved contrast along with edge enhancement for weakly absorbing samples and hence it is of immense value in study of materials like carbon fiber, carbon composite, etc. This technique is also very useful for determination of coating thickness, uniformity of pyrocarbon coating on the fuel kernel particles. The applications of such fuel kernel particles demand a high-quality of uniformity and precise thickness. The thickness and uniformity of such coatings depends upon several parameters of the system during their preparation. In this paper, we have explored the use of X-ray phase-contrast techniques for the measurement of coating thickness and its uniformity. We present the results of such experiments on SiC and pyrocarbon (PyC)-coated zirconia micro-spheres. This information may be of importance in optimization of the various parameters during the deposition process. The results bring out the importance of the X-ray phase-contrast technique in materials research.