微小部X線応力測定における最小照射面積と微構造の関係に関する一考察

抄録

In order to establish an optimum local stress measurement by the sin²ψ method using micro X-ray beam, Debye-Scherrer rings of three kinds of polycrystalline Al₂O₃, and Al₂O₃-10vol%ZrO₂ were measured as a function of X-ray irradiation area. Each Debye-Scherrer ring image was obtained from image plate by Cu-Kα or Fe-Kα radiations. X-ray diffraction pattern was also detected from the measured Debye-Scherrer ring image. And then, a correlation between X-ray irradiation volume and X-ray diffraction pattern was examined for each material. The minimum X-ray irradiation volume, where X-ray diffraction pattern and local stress field were approximately equivalent to that from a myriad of grains existed in model materials, was determined. As a result, the minimum irradiation volume was found to correspond to the microstructural volume in which about 10⁴ grains existed randomly. Furthermore, by oscillating the X-ray incident angle, the minimum irradiation volume lowered at the volume in which about 2.8×10³ grains existed. Finally, it was confirmed that local stress of polycrystalline Al₂O₃ could be successfully measured by Synchrotron micro X-ray beam.