An Fe–Mn–Si–Cr shape memory alloy is applied to make crane rail fishplates. The shape recovery of the reverse martensite transformation from hcp to fcc is utilised to connect finite lengths of rail. Rails connected by normal steel fishplates gradually become separated at the joint and can be damaged by broken flakes in the gap and dents during heavy duty operation of the crane. To eliminate such problems, a sufficient and controlled compressive stress is required at the joint to resist the stress responsible for creating the gap. A quantitative estimate of the load required to separate the joint has been made to calibrate the compressive stress yielded by the reverse martensite transformation of fishplates. An innovative joining technique that ensures adequate and controlled compressive stress at the joined parts has been developed using a Fe–Mn–Si–Cr shape memory alloy together with sophisticated materials design and installation techniques.

An X-ray imaging device utilizing a high sensitivity image orthicon tube has been incorporated in the divergent Laue method of diffraction topography using a point source. An X-ray optical magnification of diffraction images has made it possible to obtain a spatial resolution better than that of the imaging device. Preliminary experiments have demonstrated that individual dislocations in silicon crystals can be displayed with a resolution of better than 25 µm.

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We realized measurement of stresses existing in very small areas on single crystals using an X-ray beam 60 µm in diameter. No such stress measurement has been feasible in the past because conventional measurement methods customarily use a polycrystalline powder material as a reference sample. Diffracted X-rays from a powder sample are weak and a long exposure time is required to obtain a diffraction pattern. Moreover, if the diameter of the X-ray beam is reduced, it is difficult to obtain a continuous diffraction ring. We thought of using a single crystal as a reference sample and eventually succeeded in measuring stresses in very small areas. We also examined the measurement precision of this method. As for the medium of recording X-ray diffraction patterns, we employed an imaging plate and tried to shorten the measurement time. We also clarified that high-precision stress measurements can be performed, even with the imaging plate. As a result, we were able to measure stresses in a silicon single crystal with an X-ray beam of 60 µm diameter in 16 min of exposure time.

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