Masugu Sato

The Advanced Automation for Powder Diffraction toward Industrial Application

A highly automated system for powder diffraction with synchrotron radiation was installed on the large Debye‐Scherrer camera at the BL19B2 Engineering Science Research I beamline of SPring‐8. Combined with a sample transfer and an automated centering system, we have succeeded in increasing the ratio of exposure time in the user beam time to 85%. The proposed system can be applied to a wide range of industrial uses.

Gravity Effect on Copper Corrosion

With a new gravity electrode by means of centrifugal force, gravity effect on copper corrosion in nitric acid was examined. The electrode system could control the gravity field up to 350 g by changing rotation speed. The experiments were performed in three different configuration modes of copper electrode; parallel, upward- vertical and downward-vertical to the gravity. After immersing copper electrode into 3 moldm -3 HNO 3 solution, under given gravity, corrosion currents and weight losses of the electrodes were measured. Consequently, it became obvious that copper corrosion is drastically protected in high gravity field. As long as the gravity is not so high, the upward-vertical mode indicated the most drastic change in corrosion rate with increasing gravity. In high gravity field, the corrosion rates in all modes converged to negligibly small values. On the contrary, in the solution with 0.01 moldm -3 HNO 3 + 3 moldm -3 NaNO 3 , the corrosion rate increased with increasing gravity. All these results was attributed to the facts that the convection flow induced by gravity affects the corrosion processes in different two ways; one is the blocking effect on copper dissolution and another the promoting effect on nitric-acid decomposition.

Improvement in Stability of SPring‐8 Standard X‐Ray Monochromators with Water‐Cooled Crystals

SPring‐8 standard double‐crystal monochromators containing water‐cooled crystals were stabilized to a sufficient level to function as a part of optics components to supply stable microfocused x‐ray beams, by determining causes of the instability and then removing them. The instability was caused by two factors—thermal deformation of fine stepper stages in the monochromator, which resulted in reduction in beam intensity with time, and vibrations of coolant supply units and vacuum pumps, which resulted in fluctuation in beam intensity. We remodeled the crystal holders to maintain the stage temperatures constant with water, attached x‐ray and electron shields to the stages in order to prevent their warming up, introduced accumulators in the water circuits to absorb pressure pulsation, used polyurethane tubes to stabilize water flow, and placed rubber cushions un der scroll vacuum pumps. As a result, the intensity reduction rate of the beam decreased from 26% to 1% per hour and the intensity fluctuation from 13% to 1%. The monochromators were also modified to prevent radiation damage to the crystals, materials used as a water seal, and motor cables.

Enhancement of Reaction of Zinc on Superficially Nanocrystallized IF Steel by Near Surface-Severe Plasitc Deformation

The reaction between the zinc plate (ZP) and the IF steel with near surface ultra fine grains (NSUFG) structure with grain size of about 89 nm was studied in temperature range of 473K to 623K in order to elucidate the temperature dependence of the reactions and its mechanism, by comparison with the reactions of ZP to coarse grains (CG) sheet, superficial cold rolled CG sheet (CG+R) and superficial cold rolled NSUFG sheet (NSUFG+R). It was found that this NSUFG structure considerably affected reactions between IF steel and ZP. There was almost no effect of superficial cold rolling on their reactions, but the NSUFG structure dramatically enhanced the reactions. The incubation times for appearance of the reaction layer and its layer width of ZP /(NSUFG or NSUFG+R) reactions are shorter and thicker than those of the ZP/(CG or CG+R) ones. The activation energy for reaction was 107kJ/mol, which indicates that the volume diffusion in zinc side and the grain boundary diffusion in the iron side play an important role in the reaction. The layer growth up to the layer thickness less than about 10µm was controlled mainly by the interface reaction and it over about 10µm mainly by the diffusion mass transfer.

High-throughput and automated SAXS/USAXS experiment for industrial use at BL19B2 in SPring-8

A highly automated system combining a sample transfer robot with focused SR beam has been established for small-angle and ultra small-angle X-ray scattering (SAXS/USAXS) measurement at BL19B2 for industrial use of SPring-8. High-throughput data collection system can be realized by means of X-ray beam of high photon flux density concentrated by a cylindrical mirror, and a two-dimensional pixel detector PILATUS-2M. For SAXS measurement, we can obtain high-quality data within 1 minute for one exposure using this system. The sample transfer robot has a capacity of 90 samples with a large variety of shapes. The fusion of high-throughput and robotic system has enhanced the usability of SAXS/USAXS capability for industrial application.

Measurement of Distributions of Local Internal Stress Near Grain Boundary in SUS316 by EXDM Using White X-ray Micro Beam

The distributions of the local internal stress near the grain boundaries in 20 % cold-rolled SUS316 stainless steel were measured under the external tensile stress of 0 and 300 MPa using the Energy-dispersive X-ray Diffraction Microscopy (EXDM) technique at BL28B2 of SPring-8. The local internal stresses near the grain boundaries were successfully evaluated. The results indicated that the evidence that the internal stress concentration was occurred at the grain boundaries under the external tensile stress.

Diffusion Reactivity between Zinc Plate Layer and Nanocrystalline Surface Layer of IF Steel by Near Surface-Severe Plastic Deformation

The effect of near surface-ultrafine grain (NSUFG) layer with grain size of about 90nm on the solid reaction between Ti-added ultra-low carbon interstitial free steel sheet and electroplated zinc layer (ZP) was basically investigated at 473K and 573K, in comparison with the reactions of the coarse grains IF steel sheet (CG-IF) and the ZP. The NSUFG structure dramatically changes the reactions between ZP and IF steel, as follows; (1) the incubation times for the formation of reaction layers, pseudo-z-phase, are quite shorter for the NSUFG/ZP reactions than the CG/ZP ones, (2) in the early stage of annealing the former has the smooth interfaces of pseudo-z-phase layers but the latter has wavier ones like a stone wall, (3) the thickness of the pseudo-z-phase layer of the former is thicker than that of the latter, (4) some cracks are observed in NSUFG layers while no crack in coarse grain IF steel, and (5) the subsequent layer appears in the reaction between pseudo-z-phase and NSUFG layers former after long annealing by the blast-like break of the interface.