Developments in In Situ Nanomechanical Testing J. D. Nowak, R. C. Major, J. Oh, Z. W. Shan, S.A. Syed Asif, and O. L. Warren Hysitron, Inc., 10025 Valley View Rd, Minneapolis, MN 55344, USA. The past decade has seen a notable interest in in situ studies in the scanning and transmission electron microscopes (SEM and TEM), which has in turn driven a number of advancements in in situ testing systems. The miniaturization of certain critical components has transformed historically qualitative techniques into fully quantitative complementary test systems. This miniaturization is important because the physical constraints of the SEM and TEM are quite demanding, making compact systems not only desirable, but also geometrically necessary. Of particular interest, small-scale transducers which can accurately measure force and displacement have been developed, which can make what would otherwise be a simple in situ nanomanipulator a fully quantitative nanomechanical test instrument [1]. With these systems it is possible to pair the high sensitivity of nanoindentation with the high spatial resolution of electron microscopy. Here we report on the development of a series of compact vacuum-compatible nanomechanical test instruments for the SEM and TEM [1-2]. Nanoscale structures (such as the nanoparticles shown in Fig 1) are often difficult to test because of the inherent challenges imposed by the size of the samples involved and the scale at which the phenomena in question occur, but with in situ techniques simultaneous imaging and nanomechanical testing is possible. One notable advancement is the integration of simultaneous electrical contact resistance (ECR) measurements (Fig 1). Using a conductive indenter probe and a current/voltage source, a time-based correlation between force, displacement, current, and voltage measurements can be determined. Other new developments include an in situ tensile apparatus and a miniaturized heating stage has been designed for simultaneous in situ heating during mechanical testing with rapid heating rates and extremely low thermal drift. Depending on microscope configuration, tests can be further coupled with complementary techniques such as XEDS and EBSD [3]. The present work will describe new developments in in situ testing techniques, highlighted by application examples including compression studies of nanoparticles [4-5] and nanopillars [6], bending studies of nanowhiskers, as well as thin film nanoindentation [2]. References [1] O. L. Warren et al., Materials Today 10 (4) (2007) 59. [2] K. A. Rzepiejewska-Malyska et al., J. Mater. Res. 23 (7) (2008) 1973. [3] Niederberger, Mat. Sci. Eng. A submitted (2010). [4] J. D. Nowak et al., Scripta Mater. In Press (2010). [5] Z. W. Shan et al., Nature Materials 7 (12) (2008) 947. [6] Z. W. Shan et al., Nature Materials 7 (2) (2008) 115. [7] The authors gratefully acknowledge the staff and facilities at Lehigh University and at the Institute of Technology Characterization Facility, University of Minnesota, a member of the NSF-funded Materials Research Facilities Network, where portions of this work were performed. 462 doi:10.1017/S1431927610062598 Microsc. Microanal. 16 (Suppl 2), 2010 © Microscopy Society of America 2010 https://doi.org/10.1017/S1431927610062598 Downloaded from https://www.cambridge.org/core. IP address: 34.228.24.229, on 18 Jun 2020 at 22:22:34, subject to the Cambridge Core terms of use, available at https://www.cambridge.org/core/terms.