Hiroyuki Toda 교수

Synchrotron X-ray microtomography has been utilized for the in-situ observation of steady-state plane-strain fatigue crack growth. A high-resolution experimental configuration and phase contrast imaging technique have enabled the reconstruction of crack images with an isotropic voxel with a 0.7 µm edge. The details of a crack are readily observed, together with evidence of the incidence and mechanical influence of closure. After preliminary investigations of the achievable accuracy and reproduci

The single-distance phase retrieval technique was applied to contrast-enhanced imaging of the dual-phase microstructure of a ferrite/martensite dual-phase with only 1.4% difference in density between the two phases. Each high-resolution absorption-contrast image was registered with a corresponding phase-contrast image, to analyse damage evolution behaviour. The loading step at which each microvoid was nucleated was identified by tracking the microvoid throughout tension, together with its nuclea

Al-10Mg alloys, which are highly susceptible to SCC, were prepared with various β precipitate morphologies. Interrupted in-situ tensile tests were conducted under synchrotron X-ray radiation, employing a recently developed X-ray microtomography technique that combines high-energy, applicability to metallic materials, and ultra-high resolution. Preferential dissolution of the β phase along grain boundaries, and incidental intergranular and transgranular fracture, were observed in 3D. A drastic de

Microtomography combined with hard x-ray imaging microscopy has been employed to observe nanoscopic features in a material, which has, to date, only been done by the transmission electron microscopy (TEM). Here, the authors show a characteristic microstructure in an aluminum alloy, such as a slant gap between growing precipitates that impinge on each other due to the presence of a solute-depleted zone. Such observation is not possible by conventional projection microtomography even using the hig