2020 年 60 巻 10 号 p. 2246-2254
Transmission electron microscopy (TEM) is a powerful tool for analyzing fine precipitates because it can measure the size of the precipitates directly. In contrast, small angle X-ray scattering (SAXS) can observe much larger volumes and yield statistical quantitative results. However, the consistency between results obtained by SAXS and TEM has not been well investigated, especially in the case of precipitates having anisotropic shapes. In this study, the quantitative capability of SAXS was investigated by comparing SAXS and TEM results for TiC precipitates contained in high-strength steel. Samples with various size distributions of TiC precipitates were prepared. The average size, number density and volume fraction of TiC were obtained by SAXS analysis of these samples using a sphere or a disk form factor. Regardless of the form factor, the average size and volume fraction were almost the same, whereas the number density differed by one order of magnitude. The average size of TiC precipitates measured by SAXS analysis was consistent with that obtained by TEM. Since it is considered that the difference in number density depending on the form factor is attributed to an error due to the overestimation of the size distribution width, the average number density was defined to correct for this. The average number density calculated from the results using both form factors agreed well and were reasonable. It was found that using a sphere form factor with good convergence is effective for obtaining average information concerning the precipitates.
