I have been engaged in the study of mechanical properties of materials for nearly 50 years. My early work was on high temperature creep and fracture of metals, focusing on techniques for measuring internal back stresses in deforming metals and featuring the modeling of diffusional deformation and cavity growth processes. My students and I also studied high temperature dispersion strengthening mechanisms and described the effects of threshold stresses on these creep processes. Since the mid-1980's we have focused most of our attention on the mechanical properties of thin film materials used in microprocessors and related devices. We have developed many of the techniques that are now used to study of thin film mechanical properties, including nanoindentation, substrate curvature methods, bulge testing methods and the mechanical testing of micromachined (MEMS) structures. We are also known for our work on the mechanisms of strain relaxation in heteroepitaxial thin films and plastic deformation of thin metal films on substrates. In addition we have engaged in research on the growth, characterization and modeling of thin film microstructures, especially as they relate to the development of intrinsic stresses. Some of our recent work dealt with the mechanical properties of nanostructures and with strain gradients and size effects on the mechanical properties of crystalline materials. Our most recent work deals with the mechanical properties of lithiated nanostructures that are being considered for lithium-ion battery applications.
Last modified Fri, 31 May, 2013 at 10:02
|Fracture of crystalline silicon nanopillars during electrochemical lithium insertion||S.W. Lee, M.T. McDowell, L.A. Berla, W.D. Nix, Y. Cui||Proceedings of the National Academy of Sciences of the USA||01-2013|
|Size-dependent fracture of Si nanowire battery anodes||I. Ryu, J.W. Choi, Y. Cui, W.D. Nix||Journal of the Mechanics and Physics of Solids||01-2013|
|Size dependence of the yield strength of fcc and bcc metallic micropillars with diameters of a few micrometers||S.W. Lee, W.D. Nix||Philosophical Magazine||01-2012|
|Novel Size and Surface Oxide Effects in Silicon Nanowires as Lithium Battery Anodes||M.T. McDowell, S.W. Lee, I. Ryu, H. Wu, W.D. Nix, J.W. Choi, Y. Cui||Nano Letters||01-2011|
|Size effect in compression of single-crystal gold microparticles||D. Mordehai, S.W. Lee, B. Backes, D.J. Srolovitz, W.D. Nix, E. Rabkin||Acta Materialia||01-2011|
|Effects of focused-ion-beam irradiation and prestraining on the mechanical properties of FCC Au microparticles on a sapphire substrate||S.W. Lee, D. Mordehai, E. Rabkin, W.D. Nix||Journal of Materials Research||01-2011|
|Interconnected Silicon Hollow Nanospheres for Lithium-Ion Battery Anodes with Long Cycle Life||Y. Yao, M.T. McDowell, I. Ryu, H. Wu, N.A. Liu, L.B. Hu, W.D. Nix, Y. Cui||Nano Letters||01-2011|
|Extracting thin film hardness of extremely compliant films on stiff substrates||S.M. Han, E.P. Guyer, W.D. Nix||Thin Solid Films||01-2011|
|Dislocation junctions and jogs in a free-standing FCC thin film||S.W. Lee, S. Aubry, W.D. Nix, W. Cai||Modeling and Simulation in Materials Science and Engineering||01-2011|
|Micro-pillar plasticity controlled by dislocation nucleation at surfaces||W.D. Nix, S.W. Lee||Philisophical Magazine||01-2011|
Member of National Academy of Engineering; Fellow of the American Academy of Arts and Sciences; Member of the National Academy of Sciences; Acta Metallurgica Gold Medal, 1993; Educator Award, The Metallurgical Society, 1995; ASM Gold Medal, ASM International, 1998; Honorary Doctorate of Engineering, Colorado School of Mines, 2001; Nadai Medal, ASME, 2001; A.E. White Distinguished Teacher Award, ASM International, 2002; Albert Sauveur Achievement Award, ASM International, 2003; Honorary Doctorate of Engineering, University of Illinois, Urbana-Champaign, 2007; Von Hippel Award, Materials Research Society, 2007; Fellow, Materials Research Society, 2011; Heyn Medal, German Society of Materials Science, 2011; Honorary Doctorate of Science, Northwestern University, 2012.