Please see seminar notice below: MATERIALS SCIENCE AND ENGINEERING SEMINAR Failure Analysis of Micron Scaled Silicon Under High Rate Tensile Loading By: Steven J. Dubelman Ph.D. Final Examination Advisor: Prof. W. Chen ABSTRACT Structures have been built at micro scales with unique failure mechanism not yet well understood, in particular, under high-rate loading conditions. Consequently, MEMS devices suffer from inconsistent performance and insufficient reliability. This research aims to understanding the failure mechanisms in micro-scaled specimens deforming at high rates. Single crystal silicon micro beams that are 4 microns thick are subjected to tensile loading at average strain rates of 100 s-1 using a miniature modified Kolsky tension bar. A capacitance displacement system and piezoelectric load cell are incorporated to measure the strain and stress of the silicon micro beams directly to ensure precision. Extreme fragmentation of the beams occurs during failure and this phenomenon is observed using a high speed camera. A debris retention system is used to capture the silicon fragments for direct inspection using a Scanning Electron Microscope. The failure mechanism of the micro beams is attributed the presence of multiple micron scaled surface defects rather than any one large critical flaw. Date: Thursday, March 28, 2013 Time: 7:30 A.M. Place: ARMS 1028 Thank you, Lisa Stacey Secretary/Development Assistant Purdue University School of Materials Engineering 765/494-4100