In Situ Study of Hydrogen Accumulation in the E110 Zirconium Alloy during Gas-Phase Hydrogenation by the Methods of Thermal Desorption Spectroscopy and Synchrotron X-Ray Diffraction Analysis

The method of thermal desorption spectroscopy (TDS) implemented on an automated Gas Reaction Controller LPB complex and the procedure for conducting experiments on the study of hydrogen accumulation using the TDS method are described. The use of the complex made it possible to perform experiments on TDS immediately after saturation with hydrogen without removing the samples from the vacuum environment. The operating temperatures of the complex were in the range from 20 to 1000 degrees C. The heating rate was kept constant and could be set between 0.1 degrees C/min and 6 degrees C/min. The pressure range was from 6 x 10(-8) to 1 x 10(-5) Pa when performing thermal desorption spectroscopy and from 0.02 Pa to 5 x 10(3) Pa when the samples were saturated with hydrogen. For the E110 zirconium alloy, the temperature dependence of the sorption rate was determined. Using in situ X-ray diffraction on synchrotron radiation, it was shown that during gas-phase hydrogenation in the E110 zirconium alloy (Zr-1% Nb), delta-hydrides were formed throughout the entire bulk of the material. Under thermal action, the dissociation of hydrides occurred in the temperature range of 500-550 degrees C. With a further increase in temperature, a thermally stimulated release of hydrogen occurred, accompanied by a phase transition of zirconium from the alpha to the beta phase.