Distribution of Hydride in Titanium Determined by X-Ray Diffraction-Enhanced Imaging Method with Asymmetric Reflection Analyzer

Abstract

The X-ray refraction imaging technique, diffraction-enhanced X-ray imaging (DEI) method with an asymmetric reflection analyzer was applied to determine the distribution profile of hydride in titanium. Horizontal magnification of the image by the asymmetric reflection was 9 times. Hydride was formed on titanium surface by electrolytic-charging at room temperature for 10, 25.5, 48 and 150 h. The specimen was cut into a 1-mm thick slice for cross-sectional observation. Hydride layer was observed by DEI method as a thick black or white line parallel to the surface. X-ray intensity profile of hydride was measured from the DEI image and converted to the deviation angle of X-ray by refraction using the observed rocking curve. The distribution of refraction index was calculated from the deviation angle of X-ray using Snell's low. Finally distribution of ratio of hydride and titanium, the concentration profile of hydride, was obtained from that of the refraction index. The distribution profile of hydride in titanium was determined to accuracy of the order of micrometer by means of the DEI method with asymmetric reflection analyzer.

Determination of hydrogen diffusivity depending on the hydride concentration in titanium-hydride by means of the diffraction-enhanced X-ray imaging method

“…Concentration profile of hydrogen in Fig. 5 shows complicated shape rather than that obtained by symmetric analyzer [15]. The profile carves in Fig.5 were not able to simulate using a solution of the one-dimensional diffusion equation with constant diffusion coefficient.…”