高分子基材上のパラジウム薄膜における水素吸蔵に伴うはく離解析

抄録

Palladium has a high chemical affinity with hydrogen and is used as catalysts for the synthesis of organic compounds, fuel cells, and membranes of hydrogen purification and separation. It is expected as a material that plays an important role in hydrogen transportation and storage, hydrogen detection sensors, and so on. Palladium that has absorbed hydrogen undergoes phase transformations and that shows significant volume expansion. Palladium thin film deposited on a substrate such as silicon wafer or polymer films, the mismatch of volume expansion may bring about the delamination of palladium thin film. Therefore, it is important to evaluate the interfacial stress for the integrity of thin film structures. In this study, palladium thin film, which has the length of 2b and the thickness of h, on semi-infinite elastic substrate is analyzed with the volume expansion of palladium thin film due to hydrogen absorption. By solving a non-linear integral equation, mode II stress intensity factor at the edge of palladium thin film is obtained. The results show that a chemo-mechanical coupling parameter, η, shows the important role on the mode II stress intensity factor. As the coupling effect is strong, which means that η increases, the mode II stress intensity factor increases, and it may bring about the edge delamination of palladium thin film.