Mechanical Behavior and Microstructure of Metallic Thin Films etc.
Plasticity in Freestanding Cu Thin Films (Yong Xiang)
The microstructure and mechanical behavior of freestanding Cu thin films with thickness ranging from sub-micron to a few microns were systematically investigated. The films were synthesized by means of either sputtering or electroplating. Freestanding membranes were fabricated using standard Si micromachining technology. Microstructure was characterized thoroughly using a variety of techniques such as SEM/FIB, TEM, AFM, EBSD, and XRD. A computerized bulge test apparatus with automated data acquisition was constructed to test freestanding thin films. The influence of the microstructure, film thickness, and surface passivation on the elastic-plastic behavior of the films was quantitatively evaluated. Comparison of the experimental results with discrete dislocation simulations and strain gradient plasticity reveals the deformation mechanisms for materials at micron- and nano-scales.

Publications:
Y. Xiang and J.J. Vlassak, "Bauschinger and size effects in thin-film plasticity", Acta Materi. 54, 5449-5460 (2006). (Download)
L. Nicola, Y. Xiang, J. J. Vlassak, E. Van der Giessen and A. Needleman, "Plastic deformation of freestanding thin films: experiments and modeling", J. Mech. Phys. Solids 54(10), 2089-2110 (2006). (Download)
Y. Xiang, T. Y. Tsui, and J. J. Vlassak, "The mechanical properties of freestanding electroplated Cu thin films", J. Mater. Res. 21(6), (2006). (Download)
Y. Xiang and J. J. Vlassak, "Bauschinger effect in thin metal films", Scr. Mater. 53, 177-182 (2005). (Download)
Y. Xiang, J. J. Vlassak, M. T. Perez-Prado, T. Y. Tsui, A. J. McKerrow, "The effects of passivation layer and film thickness on the mechanical behavior of freestanding electroplated Cu thin films with constant microstructure", Mater. Res. Soc. Symp. Proc. 795, 417-422 (2004). (Download)
Y. Xiang, X. Chen and J. J. Vlassak, "The mechanical properties of electroplated Cu thin films measured by means of the bulge test technique", Mater. Res. Soc. Symp. Proc. 695, L4.9 (2002). (Download)


