抄録
Titanium nitride TiN has considerable hydrogen impermeability and is expected as a prevention coating of hydrogen gas parmiation for a cladding tube of metal hydride fission fuel. The TiN coating produced with plasma process is very complicated because the cladding tube is not wide enough to create stable plasma. A simple reactive evaporation process was selected for coationg process of TiN films to inner wall of narrow tube or stainless steal tube. The films were thermally deposited on stainless steel sheets coiled around inner wall of silica glass tubes. Nitrogen as a reactive gas was introduced into the vacuum chamber with pressure range of 5.0×10-2 Pa ∼ 3.0×10-1 Pa. Thin films with gold color were obtained. From XRD measurement of films, distinct diffraction patterns of TiN phase were observed. A reactivity of N2 gas molecules with Ti atoms in Ti-N film formation has measured quantitatively. The reaction probability of N2 molecules rN2 is defined as the ratio of the absorbing rate of N2 on Ti surface AN2 to the rate of N2 impingement ZN2. Reactive evaporation process exhibits the highest N2 reaction probability rN2 ≅ 0.05. It was the similar value of rN2 with Ti film prepared by ARE plasma processes.
