Quantitative In-Situ TEM Tensile Testing Apparatus

The Department of Energy supports collaborative research centers for electron beam microcharacterization of materials. Within these facilities, in situ transmission-electron-microscopy (TEM) tensile testing has been a powerful tool for revealing underlying physical mechanisms when materials are subjected to stress. However, all commercial in situ TEM tensile holders suffer from the absence of quantitative, load-displacement sensing ability and complexity in sample preparation. Consequently, the potential use of in situ TEM tensile holders for quantitative measurement has been hindered substantially. This project will develop a new tensile testing device for operation inside a TEM, not only yielding quantitative load-displacement data concomitant with real-time images of the microstructural behavior, but also simplifying the sample preparation procedure. To accomplish these objectives, a miniature force-displacement transducer, capable of electrostatic actuation and capacitive displacement sensing, will be integrated into the detachable part of an in situ TEM holder. This detachable part, with sample, will be designed for easy insertion into the chamber. Phase I will develop the control hardware, software, and a tensile holder,with its detachable part consisting of a force-displacement transducer. The fully-integrated apparatus will then be tested in a TEM. Commercial Applications and other Benefits as described by the awardee: The technology should enable in situ TEM tensile to become one of the most important nanometer-scale, microstructure, mechanical property correlation tools for materials development. Although the scientific community has expressed considerable interest in studying deformation mechanics inside a TEM, no quantitative tensile devices are available that can fit inside the confined space of a TEM. This indicates an emerging market for the in situ TEM tensile device. Potential customers include materials research facilities in federal laboratories, academia, and industry.