Thermal Desorption of Hydrogen from Titanium, Zirconium Alloy Zr-1% Nb, and the Thin-Film Ti/Zr-1% Nb System

The results of studying the interaction of hydrogen with commercially pure titanium VT1-00, zirconium alloy Zr-1% Nb and the Ti/Zr-1% Nb system are presented. The Ti/Zr-1% Nb system is obtained by the plasma-immersion ion implantation of titanium from a vacuum-arc discharge into Zr-1% Nb zirconium alloy. The results of X-ray phase analysis of the Ti/Zr-1% Nb system and the depth distribution profiles of chemical elements measured by high-frequency glow-discharge spectroscopy before and after titanium implantation into zirconium alloy, as well as after saturation of the samples of the obtained system with hydrogen, are presented. It is shown that at a titanium-ion current density of 5 mA/cm(2) and bias potentials of 500, 1000, and 1500 V applied to the sample, a thin (similar to 300 nm) nanostructured layer containing mainly titanium is formed in the implanted surface region of the sample. When the Ti/Zr-1% Nb system is saturated with hydrogen (by the Sieverts method), titanium and zirconium hydrides are formed in this region. The possibility of detecting (by the method of thermally stimulated gas evolution) thin nano-structured layers of titanium hydrides, to which X-ray phase analysis method is not sensitive, is proved. Data are obtained on the process of hydride formation upon saturation of the Ti/Zr-1% Nb system with hydrogen at different concentrations in the range 70-300 ppm.