Determining the stress-strain behaviour of small devices by nanoindentation in combination with inverse methods

摘要: The ongoing miniaturisation of thin films, coatings, micro-electromechanical systems (MEMS) components and devices demands for new characterising tools methods. Conventional mechanical tests cannot be readily applied to small scales, first because one can expect properties such small-scale materials second minuscule samples are difficult handle in conventional experiments as tensile tests. Here we present a method determining the LIGA (German acronym 'Lithographie, Galvanoformung und Abformung') processed MEMS, watch parts devices. is based on reverse analysis load-displacement data obtained from nanoindentation that performed micrometer sized volumes. To validate typical applications microengineering, comparison microtensile presented this paper. showed elastic modulus all tested was systematically about 15% higher than values testing, which attributed different size microstructural levels probed. numerical simulation allowed estimate true stress-true strain relationship up 30%, whereas rheology determined 5% only.