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报告内容摘要：
The delamination of thin coating films from substrates is a critical issue for the reliability of micro- and nanoelectronic devices. Scratch test and peel test are widely employed to measure the interface strength of thin coating. However, results of scratch test usually depend on the thickness and hardness of coating. In peeling test, there is a problem in cramping of weak or brittle film specimens. On the other hand, nano-indentation techniques are widely applied to evaluate the mechanical properties of thin films such as hardness, elastic modulus and viscoelasticity. Application of nano-indentation method to measure the interface strength between films and their substrates is receiving increasing attention. During indentation tests, the information obtained is the indentation load (P) and indentation depth (h) relations (i.e. P-h curve) along with the indentation impression. Therefore, it is necessary to develop a suitable method for evaluating the interfacial strength from those limited information. The energy dissipation during indentation tests for a coating layer on an elastic substrate is analyzed by the finite element method with the damage-based cohesive zone model. Focusing on the discontinuous point during the indentation tests and introducing the balance of energy before and after the onset of delamination, the evaluation method of the interfacial strength from P-h curve is introduced. The applicability of the method is examined by the experiment on PI coating / Si substrate specimen with deferent coating thickness. It is shown that small scale yielding condition does not hold for thinner coating thickness specimen and the interfacial strength is underestimated by the method. Rate dependency of indentation load and influence of plastic deformation is discussed and a revision of method is introduced.

报告人简介：
Dr. Kikuo Kishimoto is currently a Professor of the Department of Mechanical Sciences and Engineering and a Vice dean of School of Engineering, Tokyo Institute of Technology. He received his B.S. degree in 1975, M.S. degree in 1977, and Doctor of Engineering degree in 1982 from Tokyo Institute of Technology. He worked as a Research Associate and Associate Professor at Tokyo Institute of Technology from 1977 to 1995. During this period, he was a Visiting Scholar at Cambridge University from 1987 to 1988. In 1980 and 2000, he was awarded the JSME Medal for Best Paper for his contributions to dynamic fracture mechanics and interfacial mechanics, respectively. He also received the Best Paper Award from Japan Society of Corrosion Engineering in 1993, Society of Materials Science Award for Academic Contribution in 2006 and JSME Materials and Mechanics Division Achievement Medal in 2007.