Study on Correlation between Minimum Irradiation Area and Microstructure in Micro X-Ray Stress Measurement
Yoshihisa SAKAIDA
Abstract:In order to establish an optimum local stress measurement by the sin2y 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-K or Fe-K 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. Key Words:Micro X-ray stress measurement, Microstructure, Irradiation area, Ceramics, Synchrotron radiation