The Development of a High Rate Tensile Testing System for Micro Scaled Single Crystal Silicon Specimens
Date of this Version3-2014
Structures have been built at micro scales with unique failure mechanisms that are not yet understood, in particular, under high-rate loading conditions. Consequently, microelectromechanical systems (MEMS) devices can suffer from inconsistent performance and insufficient reliability. This research aims to understand the failure mechanisms in micro-scaled specimens deforming at high rates. Single-crystal silicon (SCS) micro specimens that are 4 mu m thick are subjected to tensile loading at an average strain rate of 92 s(-1) using a miniature Hopkinson tension bar. A capacitance displacement system and piezoelectric load cell are incorporated to directly measure the strain and stress of the silicon micro specimens. The average dynamic elastic modulus of the silicon micro specimens is measured to be 226.8 +/- 18.50 GPa and the average dynamic tensile strength of the silicon is measured to be 1.26 +/- 0.310 GPa. High-speed images show that extensive fragmentation of the specimens occurs during tensile failure.
Nanoscience and Nanotechnology