Development of Measuring System for Stress by Means of Image Plate for Laboratory X-ray Experiment

A single exposure X-ray incidence method for determining stress using the whole part of the Debye-Scherrer ring was studied. An image plate (IP) was used in this study as an area detector. A stress measuring system using an X-ray two-dimensional detector was developed. This was designed in order to be used in the authors’ X-ray laboratory. The background and the purpose of this study is to point out that it is possible to carry out the stress measurement using a two-dimensional X-ray detector, and that this method has advantages such as it is less time-consuming and its effective use of the diffraction data from the material. However, a sufficient amount of studies on the measuring systems for this kind of X-ray stress measurement have not been made, so that both the accuracy and the reliability of the final results obtained are not satisfactory at the present stage. In particular, the accuracy of the determination of the exact center of the diffraction ring, flatness of the measuring plane of IP at a microscopic level, and exact distance between the specimen and the detector (IP) is required in order to determine stress as correctly as the ordinary X-ray goniometer method (the sinψ method). In this study, the authors attempted to develop a measuring system that satisfies the above requirements. The validity of the authors’ new equipment was confirmed by experiment, in which the specimen was loaded under the bending stress during the X-ray stress measurement, and the stresses obtained were compared to the applied ones.